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2019 Buyer’s Guide to Mil-Spec Fasteners

7 things you need to know

If you sell to the military either directly or indirectly, then you are probably familiar with Mil-spec fasteners. But, what exactly are they and what should you know before buying them? We’d like to help you out with this Seven point buyer’s guide.

  1. What does Mil-spec mean anyway?

Mil-spec or MIL-STD, is the informal name for the military standard the U.S. Department of Defense uses in the production of military equipment. Critical fasteners and components used in the production, repair and maintenance of this equipment are classified as “Mil-spec” fasteners. These parts are usually designated by an AN, MS, NAS or NASM prefix followed by a part number (i.e. MS24693C-4). Each of these prefixes is an abbreviation as follows:

  • AN: Army-Navy AeronauticalMS24693C
  • MS: Military Standard
  • NAS: National Aerospace Standard
  • NASM: Metric measurements of an NAS part

  1. What’s the difference between Mil-spec and commercial fasteners?

Mil-spec fasteners look a lot like their civilian cousins, but these little guys are made to a specific standard that defines in detail, the screw’s attributes, including: dimensions, tensile strength, hardness, threads, drive type, material qualities and plating, just to name a few. Mil-spec fasteners are even traceable by lot to designated manufacturers. Since Mil-Spec fasteners are often used in aerospace applications and aircraft, they are subject to extreme stress, pressure and force and require workmanship that is different than industrial & commercial fasteners.

The government maintains a list of factories that are qualified to manufacture and distribute Mil-spec fasteners. These suppliers have met all the government’s requirements and pass the highest quality control standards. This designation is called Qualified Suppliers List for Manufacturer’s [QSLM]. Commercial fasteners are not held to such specific and exacting standards.

  1. Who uses Mil-Spec Fasteners?

Mil-spec fasteners are used by anyone manufacturing or servicing military equipment. How do you know if your project requires Mil-spec parts? Often, the bill of materials (BOM) calls for specific Mil-spec grade fasteners in accordance with a part number, drawing, NIIN or NSN or procurement requirement. Some of the most common uses of Mil-spec fasteners include aerospace and naval vessels.

  1. Do Mil-Spec fasteners have different features and standards than commercial fasteners?

Mil-spec parts are manufactured and tested to strict military standards ensure performance and reliability. In general, commercial fasteners will not have the same exacting quality standards. Let’s look at a specific example and compare the Mil-Spec MS24693-C4, which is a 4-40 x 3/8 Phillips Flat 100 degree Machine screws in 300 series stainless steel, to its commercial cousin.

Features of the MS24693C-4:

  • ­ Manufactured in an QLSM approved factory
  • ­ Made/melted in the USA or other DFARs* approved country
  • ­ Materials to procurement spec FF-S-92, SAE AIR 4127
  • ­ Cleaned, descaled, passivated to AMS-QQ-P-35; AMS 2700
  • ­ Dimensions, tensile, hardness, threads, recess, head marking to AN, MS, NAS, NASM standard
  • ­ Magnetic permeability to test specs ASTM A342
  • ­ Quality Assurance to procurement spec FF-S-92 MIL-STD 1312
  • ­ Inspection system requirements per Mil-I-45208
  • ­ Full lot traceability, manufacturer’s certification and chemical and physical certification
  • ­ Available in diameters from #0 through 1/4 inch in coarse and fine thread and various lengths

Features of a 4-40 x 3/8 Commercial Phillips Flat 100 degree Machine screws in 18-8 series stainless steel:

  • ­ Manufactured per ASME B18.6.3-2002
  • ­ Thread dimensions to ASME B1.1

As you can see, the Mil-spec version is held to a higher and more exacting level of quality and testing than the commercial version. As such, the Mil-spec parts are cleaned and passivated, and tested for magnetic permeability, whereas the commercial parts are not.

  1. What level of certification is required?

Generally, a Certificate of Conformance (COC) or a record affirming a fastener has met the requirements of the relevant specification, contract or regulation is sufficient for Mil-Spec fasteners. Full certifications, which include the part name, part description, date of manufacture, lot number, chemical composition of material, and treatment of material including plating or passivation, and material test reports, are often available for a fee. It is critical to ask for the level of certification (COC, full material certs, passivation certs, etc) in advance in order to have the most efficient buying experience.

  1. Are there other factors to consider when procuring Mil-spec fasteners?

Great question! Almost a decade ago, the term “DFARS Compliant Material” came to the forefront for companies supplying parts and services to the government. The original Federal Acquisition Regulation (FAR) clause 252.225-7014 specified “A Preference for Domestic Specialty Metals.” What that means in our world is that for fasteners to be DFARS compliant, the metal used to fabricate them must be melted or manufactured in the United States or a qualifying country.

Qualifying countries include: Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Egypt, Finland, France, Germany, Greece, Israel, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, Turkey, United Kingdom of Great Britain and Northern Ireland.

Important Note: DFARS only pertains to fasteners made from “specialty metals” including: stainless steel, high alloy steel like Grade-BD, or Grade 5 Chromium steel with high chromium content.

To keep up to date with DFARs requirements, visit www.acq.osd.mil/dpap/dars/dfarspgi/current/index.html

  1. Where can I find a list of Mil-spec fasteners and specs?

The Defense Logistics agency is a great resource. They maintain a comprehensive database of specifications and drawings. They also maintain a catalog of hardware that includes NIINs and NSNs that sometimes called out in a bill of materials. Check out the following links for more comprehensive information regarding hardware:

http://www.dla.mil/TroopSupport/IndustrialHardware/ – to view catalogs of mil-spec parts and specs by category

http://quicksearch.dla.mil/qsSearch.aspx – To look up a specific part

http://www.mfsupply.com/mil-spec-fasteners-s/1823.htm – To see MF Supply’s Mil-Spec fastener stock

http://www.mfsupply.com/v/vspfiles/assets/images/MFSUPPLY_MILITARY.pdf – To download MF Supply’s Mil-spec line card

For more detailed information about Mil-Spec parts, to request a Mil-Spec Line Card or to send an RFQ, visit our website. And if you don’t see what you need listed, as always, ask us. “Finding the right screw for you” is our tag line after all!

Contact me at robin@mfsupply.com with your questions, comments or helpful hints!


Knurled Thumb Screws Buyer’s Guide

6 Things to Know When Buying Knurled Thumb Screws

  1. What is a Knurled Thumb Screw?

Knurled Thumb Screws are generally classified as part of the electronic hardware or precision fastener family and are not governed by IFI, ANSI or ASME standards. They are solid one piece screws with a cylindrically shaped oversized knurled head, a fully threaded shank construction and a blunt machine screw style end. They are used in applications where periodic manual adjustment is required and finger pressure can supply sufficient tightening torque.

Knurled Thumb Screw

Knurled Thumb Screw with Washer Face

  1. What materials and sizes are available?

Knurled Thumb Screws are readily available off the shelf in type 18-8/303 stainless steel and Aluminum. Some manufacturers stock knurled thumb screws in brass or other materials. Parts are typically supplied without any coating or finish.

Standard stock sizes for the thread diameter are Inch from 4-40 to 1/4-20 with standard lengths up 1” depending upon the manufacturer.

316 stainless steel, alloy and other exotic materials, and special diameters and lengths are available in certain sizes and/or for special order and usually involve a lead time.

  1. What information do I need for ordering?

The easiest way to order is by manufacturer part number. If you don’t have one, you’ll need to specify thread diameter, thread length, head style and material. For example: 6-32 x 3/8″ Knurled Thumb Screws with a Washer Face in Stainless Steel 18-8 is a popular Thumb screw.

Typical head styles are a modified fillister with a flat top where the head diameter is about twice the head height and does not need to be specified. Low head fillisters are available in certain sizes.

  1. What are some of the popular Fastener Brands with Functional Equivalents?

Popular OEM fastener brands include: Amatom, Cambion, Concord, Globe, HH Smith, Keystone, Lyn-tron, Misumi, Pic Design, RAF, and WM Berg. A comprehensive selection of Knurled Thumb Screws is also offered by McMaster-Carr, MSC Industrial and Grainger.

One surefire way to save money and shorten delivery time is to cross the OEM brand part on your bill of materials to a functional equivalent.

Let’s take the above example of a 6-32 x 3/8″ Knurled Thumb Screws with a Washer Face in Stainless Steel 18-8 is a popular Thumb screw.

This part is offered by the Five brands (yes Five!!) listed below under the following part numbers:

  • Grainger 2KB93
  • Lyn-tron SS7603
  • RAF 7103-SS-0
  • Mcmaster-Carr 99607A116
  • Unicorp THS1004-M07-F16

Each manufacturer has a different price point, but the general physical and chemical dimensions make them functional equivalents or Brand alternatives.

  1. Helpful Hints about Categories of Thumb Screws

There are 2 distinct Thumb Screws categories:

1) Knurled Thumb screws, which are covered here, are part of the precision screw family. They are made 2 ways: Washer face/flared collar or plain/shoulderless. They are typically stocked in aluminum and stainless steel. Other options such as narrow, high profile, slotted may also be available in certain sizes.

2) Type A and Type B Spade style thumb screws are part of the Industrial fastener family per ASME B18.6.8, along with Wing screws. Spade style thumb screws may be available in steel and in diameters up to 1/2”.

  1. What level of certification is required?

Generally, a Certificate of Conformance or a COC is sufficient for your customer. Full certification with material certs and test reports are often available for USA-made and Mil-Spec parts for a fee.

Knurled Thumb Screws at MF Supply

We offer:

  • The full range of commercial and Mil-Spec parts, including parts that are DFARS and RoHS compliant.
  • Brand names and generic equivalents.
  • Custom made parts per print in non-standard and exotic materials and finishes.
  • Inch and metric sizes.

For more detailed information about Knurled Thumb Screws, visit our website. And if you don’t see it listed, as always, ask us. “Finding the right screw for you” is our tag line after all!

For more than 40 years, MF Supply has helped American manufacturers streamline operations, saving them time and money with our sourcing expertise and unique supply chain strategies. We are a WBE/WOSB certified stocking distributor of fasteners and electronic components.

We work with the best established factories in the United States and DFARS-certified countries, and stock a huge inventory including all major brands and equivalents. MF Supply provides solutions including: same-day drop ship direct from the factory; custom sizes, materials and plating options; and DFARS parts with full paperwork and Certificates of Conformance.

We creatively solve common problems including hard-to-find parts and long lead times. Our sourcing and reworking expertise includes fast turnaround for modification of existing parts, hard to find standards and specials, special threads, non-standard diameters and lengths, exotic materials, special platings and short runs. We provide functional equivalents to expensive brand name fasteners and help our customers save money while reducing lead times.


Meet MF Supply President Robin Lieberman – WIFI@Work

Check out Women In The Fastener Industry’s interview with MF Supply President Robin Lieberman!

April 30, 2019

How did you start in The Fastener Industry?

Before becoming the President of MF Supply in 2009, my background was in Operations and Marketing. I ran call centers in the catalog and travel industries for years. But, I wanted to own my own business and be my own boss. So, I bought MF Supply through a business broker, although I knew nothing about the industry at all. Actually, I knew less than nothing :). Tom, the former owner stayed on for 3 years and taught me everything!

Now, as the President of MF Supply, I live my tag line daily. Our motto is “MF Supply, the right screw for you”, and it’s true! My amazing staff runs the day to day, yet we are small and I touch all aspects of the business, including sales, marketing, quoting, order entry, purchasing, deliveries, pickup, strategy and much more.

What is one accomplishment in your present job are you most proud of?

Two come to mind. First, MF Supply survived the financial meltdown that occured right as I bought the business. Those were scary times! Although I took no salary for almost a year, and took on a lot of debt, my team and I survived, and were able to turn the business around. In 2018 we are on course to triple our 2009 revenue.

Second, we converted the business operating and inventory management system from a paper based, dusty old cardex system (think Dewey decimal index cards with fastener history hand written on them), into a systematized digital ERP based organization. We converted almost 10,000 skus from paper to PC. At the beginning we were creating part numbers in real time. But, boy, did it pay off in the long run!

What is one favorite thing about your job?

Every single day I am challenged, usually several times. I am always sourcing new products and suppliers, learning a new technical data point, or learning about a new company. Just today I sent 10 RFQs to 7 new factories for a customized Mil-Spec part I have never sourced or sold. Fingers crossed we get the order. It’s so fun!

What is one thing we might not know about you that you would like the Fastener Industry to know?

Hmm, I have lots of secrets, but one thing that people seem surprised to find out is that I was class clown in high school. Just don’t ask me what year I graduated!

https://www.fastenerwomen.com/single-post/2019/04/30/Meet-Robyn-Lieberman—WIFIWork


New Inch & Mil-Spec Precision Shoulder Screws

MF Supply is happy to announce that in addition to our Metric Precision Shoulder Screw line, we are now offering Inch and Mil-Spec Precision Shoulder Screws, including MS51575 & MS51576. These new products are available for RFQ directly from mfsupply.com!

As your source for functional equivalents to expensive brand name fasteners, we know how to save you money and reduce long lead times commonly found with brand name fasteners.

Here is an example of a functional equivalent in action:

The following screw, available for RFQ at mfsupply.com, has a generic description as follows:
3/16” shoulder diameter x 1” long x 8-32 thread in SS18-8 (300 Series) with a hex-socket drive. Below we list seven OEM brands (yes, seven!) including their part numbers, and one Mil-Spec part number that are all functional equivalents:

    • Grainger 6JY20
    • Lyn-tron SS7431-00
    • McMaster-Carr 94035A208
    • MSC Industrial 67313726
    • Pic Design 4423
    • RAF 6931-SS
    • WM Berg PZ-14-3
    • MS51576-14

Visit our cross reference chart and plug in your part number to see if a functional equivalent is available. Popular precision shoulder screw brands include: Amatom, Cambion, Concord, Globe, HH Smith, Keystone, Lyn-tron, Misumi, Pic Design, RAF, Unicorp and WM Berg. A comprehensive selection of Precision Shoulder Screws is also offered by McMaster-Carr (tight tolerance series), MSC, and Grainger.

We encourage you to check out our Precision Shoulder Screw Buyer’s Guide on our blog where we share “Five things you need to know” to have the most efficient shopping and buying experience.

Send us your part number
to see if we can cross to a functional equivalent,
shorten lead times & save you money!

Five Reasons to buy from MF Supply

  1. Huge inventory including 18-8, 303, 316, 416, A2, A4 stainless in Inch & Metric, including major brands and functional equivalents
  2. Domestic parts with full paperwork and Certificate of Conformanceavailable
  3. Custom Sizes, Materials and Plating options available
  4. Creatively solve problems including hard to find parts and long lead times
  5. WBE/WOSB Woman Owned Certified Small Business

Brand Equivalent Case Study: Achieving faster delivery & lower costs using functional equivalents

October 9, 2018

Here at MF Supply we spend a lot of time sourcing hard to find, back-ordered or out of stock OEM hardware brands for our customers. Much like brand-name pharmaceuticals such as Tylenol and Advil are available generically (as acetaminophen and ibuprofen), some brand name fasteners are also available as “generics,” “crosses,” “alternatives” or “functional equivalents.” In the world of fasteners, a functional equivalent fastener is a part that is the same as the brand-name product in form, fit and function, including material and plating specifications. Using equivalents and alternatives to OEM brand names can be a smart way to reduce long lead times and/or cut expenses.

Check out this Case Study where an OEM brand was substituted with a functional equivalent, reducing costs by 59% and shaving lead time by over 20 weeks. This time and money savings gave the manufacturer an advantage over their competition, which helped them win the job.

Smart Manufacturers use equivalents to shorten delivery times and win business

ISSUE

A Tier 3 aerospace manufacturer of subassemblies is bidding on a job for a large international Aircraft OEM where the bill of materials calls for 172 pieces of a 1/4-28 x 1/2-20 Floating Key-Locking Insert in A286 stainless steel with a Fairchild/Alcoa Keensert® part number KNKDL428JT. As the part is in nonstock status at Alcoa, the delivery time is 28-29 weeks (yes that is half of one year which can be standard for aerospace related and mil-spec parts). Here is the dilemma – based on this delivery schedule, the manufacturer cannot meet their prospective client’s two month delivery requirement.

SUGGESTED SOLUTION

MF Supply gets a print of the part and is able to cross it to an exact functional equivalent for an alternative brand we distribute. Our factory can manufacturer and deliver the part in 4-5 weeks at 1/2 the cost of the OEM brand fastener. The alternative parts will be manufactured with full lot traceability and manufacturer’s test reports, a certificate of conformance and a DFARS statement. The client (Aircraft OEM) approves the substitution and awards the manufacturer the business based on their ability to make the 2 month delivery requirement. A Purchase Order for the Floating Key-Locking Insert is issued to MF Supply. As promised, within 5 weeks, the complete 172 inserts, with full paperwork, are delivered to the manufacturer. The subassemblies are produced and delivered to the end client on time and underbudget.

TIME SAVINGS

-MF Supply functional equivalent fasteners shorten delivery time from 28-29 weeks to 5 weeks.

COST SAVINGS

-KNKDL428JT price = $200 each. Total cost $34,400.
-MF equivalent price = $82.00 each. Total cost $14,104.
-Savings=$20,296!

SUMMARY / BENEFIT

-Cost savings of $20,296 or 59% (not a typo!).
– Tier 3 aerospace manufacturer wins bid and is awarded job.
-Work is completed on time.
-Job is more profitable due to cost savings realized on inserts.
-Job has been a repeater and a money maker for Tier 3 aerospace manufacturer.

In summary, if your bill of materials calls for an OEM brand fastener or component, find out if you must have the brand name product. In cases where a generic or equivalent alternative part will work, there might be an opportunity to save money and shorten delivery time.

How can I determine if I must use the brand name or if I can cross to a generic part?

Before you shop, check the bill of materials to see if it specifically calls out a particular brand name along with the part number. If no specific manufacturer’s name is listed, then you can typically use a generic alternative or equivalent product?. For more complete info, check out our July 27 blog for your 4 point checklist on determining if functional equivalents will work for your business.

For more information about MF Supply contact:

Robin Lieberman, President
robin@mfsupply.com
973-777-5411


Happy Manufacturing Day 2018!

Manufacturing Day® is a national celebration of modern manufacturing meant to inspire the next generation of manufacturers and occurs annually on the first Friday in October.

MF Supply was proud to be a Blue level sponsor of New Jersey Manufacturing Day, organized by the NJMEP, which brought together manufacturers, students, supporters, government representatives and industry expert speakers at the Marigold in Somerset from 7:30A-2:30p today, October 5th.

We attended 2 breakout sessions: The first session “Driving Industry Growth through Innovative Technology, Education and Government Support” featured private and public sector experts who discussed their approach to problem solving a myriad of business issues and red tape. I met the Executive Director of the NJ Business Action Center, Melanie Willoughby who is known as “The Fixer”. She told us how she helped a NJ manufacturer get a special crosswalk built on a state road so their workers could walk directly from their plant to the deli across the street. It’s the little things that count!

The second session “Women in Manufacturing Roundtable Discussion” featured three powerhouse women representing the food, machine shop and clothing/sewing manufacturing industries. It was inspiring to hear how these three women are growing their businesses in the male dominated manufacturing space. Perhaps the coolest story was told by panelist Tom Bergeron, the Editor of ROI-NJ. He introduced us to the camp Tools and Tiaras, where this part summer, his daughter learned how to solder and build from industry experts in the housing and building industries. Resources for women are expanding and the the future for Women in Manufacturing looks very bright!

Other breakout sessions included:

  • Tariffs – How to Apply For Exclusions
  • Emerging Topics in Food Safety
  • Tips for Recruiting, Retaining And Linking into Underutilized Talent Pools
  • 2018 Tax Reform – How to Make The Changes Work In Your Favor

Check out the manufacturing day activities and Manufacturing Award winner announcements in your neck of the woods by visiting your state’s Manufacturing Extension Program wesbite or the Manufacturing Day website for more info.

For more information about MF Supply contact:

Robin Lieberman, President
robin@mfsupply.com
973-777-5411


Buyer’s Guide to One and done Keensert® Ordering

keenserts installation

Your 5 point checklist to getting it right the first time

What is a Keensert®?

Keenserts® are solid bushing style inserts that are threaded on both the inside and the outside, and have wedges or “keys” attached at the top. They are generically called key-locking inserts, and are used to distribute loads and repair or strengthen threads against failures due to stripping, seizing or corrosion. They are commonly used in precision manufacturing and aerospace applications.

Although the name Keensert® is often used generically (like Band-Aid® or Kleenex®), Keensert® is the registered trademark of Huck Patents (its close cousin, the Keysert® is a registered trademark of Alcoa Fastening Systems.).

How do I simplify my buying process to get what I need to complete the job on time and right?

We are all familiar with that classic adage “Measure twice, cut once”. Nowhere is this more relevant than in the world of manufacturing. If you are involved in procurement, you are challenged with making sure you have the right parts available at the best price so your factory can deliver on time and on budget. Missing tools, incorrect paperwork and long delivery times can cause major headaches and negatively impact service levels.

Our goal is to help you make the Keensert buying process easier, which in turn will eliminate stress, reduce multiple shipments and potentially increase your profits. The result? Happier customers (and finance departments too)! So here it goes…..

  1. Make sure to order the correct part.

Due to the price, availability and high minimum order requirements of Huck or Alcoa branded Keensert® parts, using functional equivalents including Mil-Spec parts has become a common practice. Request that your supplier makes reference to the part number listed on your bill of materials on their sales order and packing slip. This will ensure you are getting the functional equivalent that you need.

If you are not ordering by part number, make sure to call out both the internal and external thread including the thread class (UNC, UNF, UNJ), the material and plating, and any special finish you need.

  1. Place blanket orders for your total project needs to get the best price and ensure availability of parts when you need them.

Most standard size non-locking miniature and thin wall / light weight Keenserts® are readily available off the shelf in 303 stainless steel or carbon steel. However, some locking style, nonstandard diameters, 4140 alloy, A286, heavy duty, extra heavy duty, solid and floating style Keenserts® are available only by special order and usually involve a long lead time. Make sure to get current price and delivery and order parts as early as possible. Many suppliers allow you to order now and ship later, which can prevent delivery delays.

If you have an ongoing project, calculate your total needs and place your order with staggered delivery dates. This will get you the best available pricing and ensure you have the parts when you need them. Remember, price breaks can start at as few as 100 pieces.

  1. Order (the correct) installation tools with Keenserts® for maximum efficiency.

Whereas most common size and material installation tools are readily available off the shelf, less popular sizes and materials might involve a lead time. Parent materials harder than RC30 or Anondized Aluminum may require that the tapped holes be broached for the keys, which requires the use of broach blades.

broaching tool

In addition, there are manual and power installation tools to choose from, so consult with your supplier on which tool is correct for your job. Note: manual tools work well for jobs up to 999 Keenserts®. For installations of 1000 Keenserts® or more, a pneumatic tool is recommended.

  1. Order the Correct drills and taps for proper installation

Although Keenserts® are installed with standard drills and taps (plus the installation tool and a hammer) each part has a specific hole/tap dimensional recommendation. The drills used are often oversized for the external thread size. When purchasing key-locking inserts, check with your production department to make sure you have everything you need for proper installation. Note: Drill is oversize see charts for proper dimensions.

Kits are handy to have in the shop and are available for most common sizes. These kits include 2+ Keenserts®, the associated drill, tap and manual installation tool along with instructions for correct installation.

  1. Request COC, MTRs, DFAR and all required paperwork on your RFQ and PO.

Since using functional equivalents including Mil-Spec parts is a common practice, make sure you have dotted your i’s and crossed your t’s when it comes to paperwork. Ask your supplier to reference the branded part number listed on your bill of materials on their COC and packing slip to make sure you are getting the functional equivalent that you need. In most cases, a Certificate of Conformance or a COC referencing the part number you ordered is all the paperwork you need. Certain aerospace customers need a complete Manufacturer’s Test Report (MTR) package including DFAR statement and passivation certs with full lot traceability. This might involve a fee, so include it in your RFQ. Whatever your requirement, include it on your Purchase Order to make sure you have what you need to satisfy your customer’s needs.

In summary, follow this handy 5 point guide when ordering Keenserts® and watch your costs decrease and your service levels soar!

For more information about MF Supply contact:

Robin Lieberman, President
robin@mfsupply.com
973-777-5411


Buyer’s Guide to Metric Dowel Pins

dowel pin

7 Things to Know When Buying Metric Dowel Pins

This guide is a follow up to our Dowel Pin Buyer’s Guide published May 2017. This post is specifically written to share with you the available options when it comes to procuring precision Metric dowel pins.

Our goal is to help simplify the buying process and guide you in the critical selection factors for this sometimes complex and confusing category of fasteners.

1. What standards are Metric Dowel Pins made to?

Metric dowel pins are tricky because they fall into two buckets:

  1. DIN / ISO standard – These metric Dowel pins are readily available in the commercial marketplace and in addition to your suppliers, can be procured through national catalogers like Mcmaster-Carr, Grainger and Holo-Krome. They come on steel and stainless steel.
  2. Precision Metric Dowel Pins – These “Precision” dowel pins are manufactured by precision component brands such as Pic Design, WM Berg and Unicorp who have their own technical specifications and are not governed by DIN or ISO standards. They are usually only offered in stainless steel through distributors of precision components.

2 . What are the specific criteria I can select for Metric dowel pins?

Here is a list of the criteria and available options available:

  • Size
  • Material
  • Hardened or Unhardened
  • End style
  • Tolerances

3 . Can you list the standard and precision dowel pins available off the shelf?

4. Which types of metric dowel pins are available in which sizes and materials?

Use this handy grid to understand the sizes and materials available in each Metric dowel pin style.

Standard
Ends
Materials
Tolerances / Fit
Hardness
Diameters
DIN7
ISO 2338
ISO 2338A
Rounded or beveled
Steel (least common)
300 Series Stainless Steel including
A1=18-8, 303, 304
A4=316
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Unhardened
M.8-M20
ISO 2338B
Rounded or beveled
300 Series Stainless Steel
A1=18-8, 303, 304
H8 diameter tolerance
Unhardened
M1.5-10
DIN 6325
DIN 6325H
ISO 8734A
ISO 8734
Rounded on one end
Beveled on one end
Alloy Steel
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Hardened to
RHC 52-62
M1-M25
Precision Unhardened
Rounded
300 Series Stainless Steel
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Unhardened
M1-M12
Precision Hardened
Rounded on one end
Beveled on one end
416 Stainless Steel
M6 diameter tolerance
Slightly Oversized
aka Press Fit
Hardened to
RHC 36-42
M2-M10

Important note: All pin options may not be available in all sizes and materials.

5. When ordering, do I need to specify the dowel pin tolerance or call out attributes such as standard, undersized or oversized fit?

Metric dowel pins can show up under DINs and ISO numbers, including : DIN 7, DIN 6325, and ISO 2338 and 8734. When ordering DIN/ISO dowel pins it is best to include the Diameter, Length, Material, DIN or ISO and tolerance. For non DIN/ISO Precision metric dowel pins, you can order by the manufacturer part number, such as Pic (MDP series), WM Berg (DM Series), or Holo-Krome.

6. Can I specify if I need radius (round) or chamfer (bevel) on the pin ends?

The pin style will depend upon the spec and the material. Precision dowel pins may come with either a double chamfer, double radius, or a radius on one end and a chamfer on the other end. Check with the handy grid above for guidance.

Important note: The configuration of the ends of unhardened metric dowel pins are at the discretion of the manufacturer. If you have a specific style requirements, you might need to special order which usually involves a minimum and a lead time.

7. What if I need domestic or DFAR certified Metric dowel pins?

If you are ordering by a Precision Manufacturer part number, you are in luck! Most of the stainless steel pins produced by Pic, WM Berg and Unicorp qualify as DFAR compliant and full certifications with material certs and test reports are often available for USA made parts for a fee.

Metric Dowel Pins at MF Supply

We offer:

  • The full range of commercial Metric Dowel pins including parts that are USA made, DFARS and ROHS compliant.
  • Metric sizes including ASME ANSI B18.8.2, DIN 7, DIN 6325, and ISO 2338 and 8734
  • Metric Precision Dowel pins including Press-Fit Series and all MD series pins in 416 and 303 Stainless Steel.
  • Brand names and generic equivalents.
  • Custom-made parts per print in non-standard sizes and exotic materials and finishes.
For more detailed information about Metric Dowel Pins, to request a line card, or to send an RFQ, visit our website. And if you don’t see what you need listed, as always, ask us. “Finding the right screw for you” is our tag line after all!
Contact me at robin@mfsupply.com with your questions, comments or helpful hints!

About Us

For more than 40 years, MF Supply has helped American manufacturers streamline operations, saving them time and money with our sourcing expertise and unique supply chain strategies. We are a WBE/WOSB certified stocking distributor of fasteners and electronic components.

We work with the best-established factories in the United States and DFARS-certified countries, and stock a huge inventory including all major brands and equivalents. MF Supply provides solutions including: same-day drop ship direct from the factory; custom sizes, materials and plating options; and DFARS parts with full paperwork and Certificates of Conformance.

We creatively solve common problems including hard-to-find parts and long lead times. Our sourcing and reworking expertise includes fast turnaround for modification of existing parts, hard to find standards and specials, special threads, non-standard diameters and lengths, exotic materials, special platings and short runs. We provide functional equivalents to expensive brand name fasteners and help our customers save money while reducing lead times.

Follow our blog at http://blog.mfsupply.com/


Smart Manufacturers Use Blanket Purchase Orders to Reduce Risk

Learn to Hedge Against Inflation through Proactive Purchasing

The world of manufacturing is filled with risks. Staff turnover, overseas competition and third party vendor issues can all threaten your service level and put pressure on your organization. But one of the biggest risks in 2018 is inflation.

Rising material prices and inflationary forces are impacting costs at every level. Master suppliers are reporting price increases of 7%+ on steel products and 10%+ on stainless steel. What is a manufacturer to do?

One of the most powerful ways to mitigate the risk of rising prices is through a proactive supply chain strategy that includes issuing Blanket Purchase Orders (BPO). With a stable price for a fixed period of time, the BPO serves as a hedge against inflation.

  1. What is a Blanket Purchase Order?

A blanket Purchase Order is a contract to buy parts at a guaranteed price within a specific time period or schedule (typically one year). For example, a manufacturer forecasts to use 10,000-12,000 pieces of an MS16555 stainless steel dowel pins annually. They issue their supplier a Blanket PO for 12,000 pins a year at a negotiated price with 12 monthly releases of 1,000 pieces. This gives them 12 months of predictable costs at today’s 12,000 piece price, rather than tomorrow’s 1000 piece price. As we start to see double digit price increases in the industrial marketplace, the savings multiply.

  1. What are the benefits of Blanket Purchase Orders?

A Blanket PO can add certainty to a business and can make your production process leaner, guaranteeing the price and availability of parts without the burden of holding the parts in stock. Suppliers also benefit because they have a predictable revenue stream. Both sides have certainty concerning quantity, price, delivery requirements and payment terms.

Beyond certainty, the top benefits of BPOs for manufacturers are:

  • Reduces unit costs through quantity discounts.
  • Guarantees pricing & reduces time spent on price negotiation.
  • Shortens lead time and eliminates stock outs.
  • Assurance of quality of products and vendors.
  • Improves efficiency of ordering, receiving and bill paying process.
  • Leaner operations with reduced stock burden.

During inflationary times, the benefits of locking in today’s prices for up to 1 year multiply.

  1. When should a manufacturer issue a Blanket PO?
  • When an item has a high minimum annual usage ($500 minimum EAU).
  • When a quantity discount can be achieved.
  • When you are already making repetitive purchases from the same supplier within a certain time period (typically 1 year).
  • When parts are used according to a production schedule.
  • When parts have a lead time.
  1. When should a manufacturer NOT issue a Blanket PO?
  • When minimum annual usage of item is low (under $500).
  • When part is only used for project work and usage in unpredictable.
  • When price is subject to change without notice.
  • When quality of product or supplier is questionable.

  1. What other factors should I consider?

The main risks when using Blanket Purchase Orders occur when BPOs are not monitored or extended past their final scheduled release, which can lead to price changes and inventory availability problems. The best way to mitigate this risk is through the use of an effective spend management tool that includes a minimum safety stock level. Collaboration with your supplier is also recommended.

The other main risk occurs when a blanket order is issued for more than the needed quantity of a specific part due to demand forecast issues or product changes. This risk can be mitigated by working with your supplier to set conditions to manage this gap, such as extending a 1 year blanket to 18 months.

Blanket Purchase Orders at MF Supply:

Here at MF Supply, we can help you effectively craft a proactive BPO strategy based on your organization’s unique needs. We offer blanket orders for up to 18 months with flexible terms and low minimums.

For more detailed information about Blanket Purchase Orders, to request a line card, or to send an RFQ, visit our website. And if you don’t see what you need listed, as always, ask us. “Finding the right screw for you” is our tag line after all!

Contact me at robin@mfsupply.com with your questions, comments or helpful hints!


Buyer’s Guide to Set Screws

where to buy set screw

8 Things to Know When Buying Set Screws

Our goal is to help simplify the buying process for this sometimes-complex category of fasteners by detailing the most critical things you must know when buying Set Screws.

  1. What is a Set Screw?

A Set Screw is a fully threaded headless screw that is traditionally classified within the socket family of products. It is generally used to fasten an object within or against another object by exerting pressure rather than holding parts together with threads. It is normally used without a nut.

  1. Who uses Set Screws?

Set Screws are used in many industrial and mechanical devices, particularly in assemblies with rotating items such as pulleys or wheels, where a component is locked onto a shaft. Designed to fasten one object inside another, Set Screws pass right through a threaded hole in the outer object and are tightened against the inner object. Pretty cool, right?

Check out this video for a demonstration of installation and application.

  1. What materials and platings are available?

The three most common Set Screw material options are alloy steel, stainless steel and brass.

The most commonly available material is hardened alloy steel with a thermal black oxide finish, as per ASME B18.3 and a Rockwell hardness of C45-53.

Stainless steel grades 18-8/303 and Metric A2 are also commonly available. Other exotic materials such as brass, 316 or A4 stainless steel, 4140 steel, 416, A286 or special finishes including zinc plating may be available for special order with a lead time.

Socket Set Screws come standard with 3A thread fit. Some sizes and materials may be available with nylon patches or pellets.

  1. What sizes are available?

In our experience, Set Screws are most commonly available in sizes 2-56 through 1″ in imperial and M2-M24 in metric diameters with a hex socket drive on one end and a cup point on the other.

  1. What information should I provide to get an accurate quote?

The easiest way to order is by part number. The most popular manufacturers of Set Screws are Holo-Krome, Blue Devil and Misumi, along with the national catalog houses like McMaster-Carr, Grainger and MSC Industrial.

If you don’t have a part number, you’ll need to provide the diameter and thread, the body length, drive and tip type, material and plating.

  1. Other than size, material and plating, what other options are available?

The other main considerations when selecting Set Screws are the drive and the point. We offer a comprehensive look at your options below.

Drives

The most common and readily available drive style is a hexagonal socket drive (think Allen wrench), however, Set Screws may also be available in slotted, six-lobe (Torx) and spline drives for certain sizes.

Points

This is where it gets interesting. The point of the Set Screw determines its function. Seven (yes, seven!) main points are available, each serving a slightly different purpose.

Cup The most common style, which is slightly cupped to meet the surface of the inner object. Used for permanent or semi-permanent installations, the Cup point provides a high level of security and control. (Metric DIN 916)

Knurled Cup A variation of the Cup point, this style has knurls for a stronger grip.

Cone A very sharp point wedges into the inner object to hold it permanently in place. With the highest holding power of all Set Screw styles, the Cone point is used for permanent settings. Note: Cone point Set Screws may cause damage to the inner object which might not be desirable in some applications. (DIN 914)

Flat – Designed for flexibility when frequently resetting or relocating objects on hard steel shafts where minimal damage to the shaft is desired. Affordable and easy to install, Flat point Set Screws can be moved without damaging the inner object. (DIN 913)

Oval The Oval point is the inverse of the Cup point. The small rounded contact surface allows slight adjustments without loosening the screw and causes minimal surface damage to the inner object. The Oval point Set Screw is the most practical type for situations where the inner and outer objects require regular adjustments.

Half-Dog Sometimes offered as a Full-Dog point, its protruding tip locks within a mating hole or slot in the shaft, for permanent setting. Half-dog/Dog points are sometimes used instead of a dowel pin. (DIN 915)

Nylon tip – Resembling a Half-Dog point, the soft nylon tip is used to grip curved or textured surfaces.

  1. What other factors should I consider?

We’ve covered the most common variables including head style, diameter and thread, length, material and plating or finish. Here are a few of the other considerations you might be faced with based on the project and the bill of materials:

Do you need domestic parts (i.e. Holo-Krome) or will imported screws work?

Do you require parts that conform to a specific mil-spec number, such as AN565, NAS1081, MS18063, MS18064, MS18065, MS18066, MS18067, MS18068, MS21342, MS51017, MS51021, MS51022, MS51023, MS51025, MS51026, MS51029, MS51031, MS51033,MS51038, MS51040, MS51045, MS51047, MS51053, MS51476, MS51477, MS51963, MS51964, MS51965, MS51966, MS51973,MS51974, MS51976, MS51977, MS51981, MS51982 with their exacting tolerances and traceability, or will standard commercial parts work?

Does your bill of materials call out a specific manufacturer, such as Holo-Krome or Blue Devil?

Make sure you have the correct installation hardware (Allen wrench or hex key) to go along with your Set Screws.

  1. What level of certification is required?

Generally, a Certificate of Conformance or a COC is sufficient for your customer. Full certification with material certs, DFARS certification and test reports are often available for USA-made and mil-spec parts for a fee.

Here at MF Supply, we offer:

  • The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.
  • Brand names (Holo-Krome) and generic equivalents.
  • Custom-made parts per print in non-standard and exotic materials and finishes.
  • Inch and metric sizes, including DIN913, DIN914 and DIN915.

For more detailed information about Set Screws, to request a line card, or to send an RFQ, visit our website. And if you don’t see what you need listed, as always, ask us. “Finding the right screw for you” is our tag line after al

What the heck are Precision Shoulder Screws?

Newsletter

Volume 8

July 23, 2014

What the heck are Precision Shoulder Screws?

Here we go again, with our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Shoulder Screw.

What is a Precision Shoulder Screw?

Shoulder Screws, which are sometimes called Shoulder Bolts or Stripper Bolts, are (generally) hex socket screws with an enlarged, unthreaded cylindrical shoulder under the head. They are comprised of 3 main parts: the head, the shoulder and the thread. They come in two basic categories, “Commercial” and “Precision”.

Commercial Shoulder Screws are made to inch standard ANSI ASME B18.8.2. The size range for the shoulder diameter is from ¼ to 2”. The thread class is 3A and the tolerance on the shoulder is +.005 / -.005.

Precision Shoulder screws are sometimes referred to as “tight tolerance” shoulder screws. They are not governed by any official ANSI or ASME standard. The size range for the shoulder diameter is from 3/32 to ½. The thread class is 2A and the tolerance on the shoulder diameter varies from +.000/-.001 to -.0005 to -.0015 depending upon the manufacturer. Now that’s precise!

Who uses Shoulder Screws?

Just as Dowel Pins and Retaining Rings are used to locate or hold parts together within a precision assembly or a fixture, so are Precision Shoulder Screws.

Yet shoulder screws are more versatile. When installed, the unthreaded shoulder acts as a shaft for rotating items such as bearings and bushings, precision spacing, machinery support, and motion guiding. Precision Shoulder screws exacting tolerances make them ideal for use with other precision components.

They are broadly used across various applications in many industries, including: aerospace, electrical motors, hydraulic equipment, instrumentation, tooling and fixtures, machinery, military and many more.

What do I need to consider when selecting Shoulder Screws?

Although Shoulder Screws are offered in a multitude of materials and styles, when it comes to the main commercial and precision offerings, there are a few main issues to consider.

Which Drive and Head Style?

Precision shoulder screws are readily available in hex socket and slotted drives. Philips drives are available in certain sizes. Torx and Star are available for special order. Typical head styles are a modified fillister with a flat top where the head diameter is about twice the head height. Low head fillisters are available in certain sizes

Which material do I need?

Precision shoulder bolts are readily available in Type 18-8/303 Stainless Steel and 416 Stainless Steel. 316 Stainless Steel, Alloy and other exotic materials are available for special order.

Are there other factors to consider?

When ordering Precision Shoulder screws, specify the Shoulder Diameter, Shoulder length, thread size, material and drive type. For example, an example of a typical Precision Shoulder screw is a ¼ shoulder x ½ long x 10-32 thread in SS18-8 with a hex-socket drive. Non-locking is the most popular style, but locking may also be available.

Precision Shoulder Bolts often show up under their brand name. Some of the most popular brands include: BERG, Concord, Globe, PIC, Lyn-tron and RAF. A comprehensive selection of Shoulder Screws is also offered by McMaster-Carr (tight tolerance series), MSC and Grainger.

Finally, Precision Shoulder Screws can also show up under their Mil-spec numbers, which include MS51575 & MS51576 and are DFARS compliant with full paperwork.

Precision Shoulder Screws at MF Supply

We offer:

The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.

Brand names and generic equivalents.

Custom made parts per print in non-standard and exotic materials and finishes.

Inch and Metric sizes.

For more detailed information on Precision Shoulder Screws, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1922

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!


What the heck are Dowel Pins?

Dowel Pins

Welcome back to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Dowel Pin.

What is a Dowel Pin?

If you have ever shopped at Ikea or assembled furniture on your own, then you are familiar with the peg shaped non-threaded wooden pins that are used to join parts together, aka as a Dowel Pin.

For the purposes of manufacturing, Dowel Pins are solid, headless cylindrical shaped straight metal pins with a centerless ground finish. Typically hardened and manufactured to precise fractional diameters and lengths, Dowel Pins come in a variety of sizes, styles, designs and materials that cause confusion among buyers, engineers and end-users alike! Today, we will try simplify this confusing category of fasteners.

Who uses Dowel Pins?

Dowel Pins are used as a hinge, shaft or pivot to locate or hold parts together within a precision assembly or a fixture.

They are broadly used across various applications in many industries, including: aerospace, electrical motors, hydraulic equipment, instrumentation, tooling and fixtures, machinery, military and many more.

Dowel Pins are popular within assemblies since they can withstand frequent insertion and removal without distortion. And production favors pins since they require no extra fastening hardware for insertion, no secondary operations and no mating parts. All this adds up to speedier production, which makes everyone in the food chain happy!

What do I need to consider when selecting Dowel Pins?

Although Dowel Pins are offered in a multitude of materials and styles, when it comes to the main commercial and Mil-spec offerings, there are a few main issues to consider.

Standard, Oversized or Undersized?

Standard series Dowel Pins are used for initial applications. They have a basic diameter 0.0002 inch over the nominal diameter. For example, a ¼ standard dowel will have a diameter between .2501-.2503.

Oversized series Dowel Pins are usually used to fit into worn holes and are generally used in the aftermarket for repairs. They have a basic diameter 0.001 inch over the nominal diameter. For example, a ¼ oversized dowel will have a diameter between .2509-.2511.

Undersized series Dowel Pins are used for inconsistent holes. They have a basic diameter -0.0002 inch under the nominal diameter. For example, a ¼ undersized dowel will have a diameter between .2500-.2498. The Mil-P-21143/2- falls into the undersized category.

Chamfer or radius on the end?

In general, commercial pins are made to inch standard ANSI ASME B18.8.2. Standard alloy pins will have a radius on one end and a chamfer on the other end. However, stainless steel Dowel Pins are often manufactured with a chamfer on both ends.

Commercial or Military?

If you or your customer needs domestically made, DFARs pins to the most exacting standards, then military may be the right pin for you!

Alloy or stainless? And which stainless for that matter?

Alloy Steel is the strongest pin available and is hardened. It can be finished with Black Oxide to provide greater rust resistance than plain alloy.

Type 416 Stainless steel is the strongest standard stainless steel offering, and is the material used for MS16555 and MS16556 series. Magnetic.

Type 18-8/303 Stainless Steel is the most commonly available stainless offered and is the standard material offered for Mil-P-21143 series.

Type 316 Stainless Steel is the most corrosion resistant stainless available and does not correlate to a Mil-spec part.

Are there other factors to consider?

Dowel Pins often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series for Dowel Pins include Mil-P-21143 (303 Stainless), MS16555 (standard series offered in both alloy and 416 Stainless Steel) and MS16556 (oversized series offered in both alloy and 416 stainless steel).

If you are not ordering by an MS or NAS Mil-Spec part number, then inch Dowel Pins conform to ANSI/ASME B18.8.2. For commercial pins, be mindful to specify the material and size tolerance that you need. Unless noted, Dowel Pins are precision ground, hardened and heat treated to meet the proper Rockwell hardness.

And remember, no hammers! When installing Dowel Pins, never drive the pin into the hole with force, always press it in for best results.

Dowel Pins at MF Supply

We offer:

The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.

Brand names and generic equivalents.

Custom made parts per print in non-standard and exotic materials and finishes.

Inch and Metric sizes including DIN 7, DIN 6325, and ISO 2338 and 8734

For more detailed information on Dowel Pins, visit us at http://www.mfsupply.com/dowel_pins_s/1925.htm


What the heck are Retaining Rings?

What the heck are Retaining Rings?

Retaining Rings

Welcome back to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Retaining Ring.

What is a Retaining Ring?
Retaining Rings are yet another way to position, locate and retain parts within an assembly. Shaped like an open ring and made of metal, Retaining Rings can be coiled from wire, stamped or laser cut. They come in a variety of styles and materials, each solving a unique fastening problem.

Generally, Retaining Rings work together with a bore or a shaft by snapping into a groove or being pushed into place to create a high strength shoulder to retain parts.

AKA – Also known as…..
The Retaining Ring is a funny little guy and answers to a bunch of different names – some of Retaining Ring’s favorite aliases are: snap rings, wire rings, circlips, retainer clips, spiral rings, wire clips, c-rings, grip rings, klip rings and push-on rings.

Who uses Retaining Rings?
Any application with a bore/housing or shaft that requires a shoulder to keep parts in place within an assembly is a candidate for using Retaining Rings.

Retaining Rings are broadly used across various applications in many industries, including: aerospace, drive shafts, electrical motors, hydraulic equipment, instrumentation, lighting assemblies, machinery, nuclear equipment and many more. Retaining Rings are very common in the automotive industry.

Why use a Retaining Ring vs. a screw or a bolt?
When a shaft or bore design that includes assembled components needs a shoulder, it can be costly to machine the shoulder, mate threaded components and fasteners together and drill and coordinate threaded holes and access holes to fasten the assembly. Retaining Rings can serve as a cost effective and time saving alternative.In addition to cost, Retaining Rings offer 2 special benefits a) they can be more resilient than screw assemblies in high vibration environments, b) they are made from less material, hence they are cleaner and gentler on the environment (aka Green!).

What styles are available?
Retaining Rings come in a variety of styles and materials. The most popular styles are: External (used on shafts), Internal (used for bores) and E-Style. The most popular materials are Carbon Spring Steel, PH15-7 Stainless Steel and Beryllium Copper. The most common finishes for Carbon Steel Rings are Phosphate, Zinc Clear and Zinc Yellow.

Are there other factors to consider?

  • As discussed, Retaining Rings are often referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Anderton, Rotor Clip, S&M and Waldes/Truarc. We can supply the brand name or generic alternatives. Note: Currently, Rotor Clip (Waldes/Truarc) and S&M are the only full-line USA manufacturers.
  • Retaining Rings often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series for Retaining Rings include: MS16624, MS16625, MS16626, MS16627, MS16628, MS16629, MS16630, MS16631, MS16632, MS16633, MS3215, MS3217 and MS90707.
  • Sizes available vary based on the style. The general range is from 1/16 to 10″. Metric sizes are also available.

Retaining Rings at MF Supply

We offer:

  • The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.
  • Brand names and generic equivalents.
  • Custom made parts per print.
For more detailed information on Retaining Rings, visit us at
And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

What the heck is a Keensert® Key-locking insert?

What the heck is a Keensert® Key-locking insert?

Image

Key-locking insert

We close out the first quarter of 2013 by introducing you to the Keensert Key-locking insert. Like its relative, the Helical wire insert, (see January 2013), the Key-locking insert was originally designed to repair parts with damaged threads.

What is a Keensert Key-locking insert?

The Key-locking threaded insert is a solid bushing style insert that is threaded on both the inside and the outside, and has wedges or “keys” attached to the top of the insert. Keensert® is the registered trademark for one of the most popular brand names for this part and is used commonly to describe this insert.

Who uses Key-locking inserts?

Generally, Key-locking inserts are used to distribute loads and strengthen or repair threads against failures due to stripping, seizing or corrosion. Key-locking inserts are commonly used in high torque and high temperature situations, and in applications where fasteners may be repeatedly removed and reassembled.

Typical applications are transmission housings, electronic equipment and suspension units. Key-locking inserts are common in the aerospace industry.

Why use a Key-locking insert vs. a Helical wire insert?

There are three main differences between Key-locking inserts and Helical Wire Inserts: Key-locking inserts are stronger than helical wire inserts, they are easier to install than helicals, and they are more expensive!

In heavy wear, high vibration and high heat situations where saving space is not a concern and hole depth is limited, Key-locking inserts are the best bet. Their “keys”, which are driven down into the tapped threads, provide a mechanical lock against rotation, especially when the mating stud or bolt will be removed frequently.

When reducing costs and minimizing space are priorities, helical wire inserts are the way to go. They are particularly useful for creating permanent strong threads in softer materials such as aluminum, titanium and magnesium alloys, and are best suited to lower heat and lower torque environments.

What styles are available?

Key-locking inserts come in four main styles: Miniature, Thin Wall, Heavy Duty Wall (general purpose) and Extra Heavy Duty. Inserts can be locking or non-locking.

Miniature Key-locking inserts are used in electronic and aerospace applications where size and strength are critical. These inserts may be installed in sheet material as thin as 1/16″.

Thinwall inserts have smaller external threads than standard heavy-duty inserts and are ideal for tight spaces where less pull-out strength is acceptable.

General-purpose Heavy Duty inserts have a thick, heavy-duty thread wall, suitable for most applications.

Extra-heavy duty inserts are used in oversized and overly worn holes.

Installation is 5 easy steps!

1) Drill with a standard tap drill and countersink with a standard 82° – 100° countersink (90° for Miniature Inserts). Note: Drill is oversize see charts for proper dimensions.

2) Tap new threads with a standard tap.

3) Screw in the insert until it is .010-.030 (.005-.015 for Miniature Inserts) below the surface. Keys locate the proper depth.

4) Drive keys down with several hammer taps on the proper installation tool.

5) You are done!

Considerations for selecting and using Key-locking inserts.

  • Inserts often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series for Key-locking inserts include: MS5180, MS51831, MS51832, NAS1394, NAS1395, NA0146, NA0147, NA0148, NA0149, NA150, NA0151.
  • As discussed, Key-locking inserts are often referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Alcoa, Fairchild, Keensert and Tridair.
  • Materials available include Carbon steel, Stainless Steel, Alloy 4140 and A286.
  • Diameters available: American – #6 to 1 1/2 ” and Metric – M4 to M24
Key-locking inserts at MF SupplyWe offer:

  • The full range of commercial and mil-spec parts
  • Products kits including single and multiple sizes
  • We are authorized distributors for Chrislynn and E-Z Lok

For more detailed information on Key-locking insert, visit us at http://www.mfsupply.com/Keensert_Style_Inserts_s/1864.htm

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!


What the heck is a Wire Insert?

Image

Today, we will introduce you to the Wire insert which was originally designed to repair parts with damaged threads, but has evolved for use in a variety of applications that save time and money and improve product reliability. Do we have your attention? Great, then read on…

What is a Wire Insert?

Wire inserts are precision-formed continuous wire coils that provide permanent, wear-resistant threads which exceed the strength of the parent material. Often underestimated, the popular misconception is that Wire inserts are intended solely for thread repair, when, in fact, they have other significant uses discussed in the next section. Not to be confused with other types of solid inserts or rivnuts, Wire inserts resemble springs and are sometimes referred to as “helicals”.

Who uses Wire Inserts?

Wire inserts are used for 3 main reasons: 1) to repair damaged threads in parts that would otherwise have to be scrapped; 2) to strengthen threads against failures due to stripping, seizing or corrosion; 3) to convert threads between inch and metric sizes. We told you they were versatile!

What styles are available?

Wire inserts come in 2 main styles: tang and tangless.

The original and widely used tang style has a prong at one end to facilitate installation. The newer tangless style is becoming popular since this style had no prongs to break off, retrieve, or lose and is easily adjusted or removed after installation. Tangless inserts are commonly used in electronic applications where loose tangs might cause damage.

Wire Inserts can be free-running or locking.

Free running is the most common style used for thread repair. The “free” diameter of the insert is larger than the installed diameter and this configuration generates balanced pressure distribution between the coils and threads.

Locking style inserts are recommended for applications that require constant torque, or are subject to stress or vibration. The locking style features a crimped turn that acts as a locking mechanism that grips the bolt or screw to prevent loosening from vibration, eliminating the need for lock wiring, lock-nuts, lockwashers, pellets/patches or other thread locking devices.

A third commonly used insert that deserves an honorable mention is a K-type Insert. Sometimes called by the brand Keensert, these externally threaded solid style inserts can be used in almost any material: aluminum, magnesium, cast iron, carbon steel, stainless steel and plastic. K-type inserts have locking “keys” that provide a mechanical lock, and are commonly used in heavy wear and high vibration situations.

5 Features & Benefits of Wire Inserts

1. Repair rather than scrap parts – Wire inserts remain the most cost effective, efficient and fastest method to repair damaged threads.

2. Stronger Assemblies – The flexibility of the insert provides a more balanced load distribution, practically eliminating thread erosion and providing better stress allocation, even in low strength materials.

3. Wear and Corrosion Resistance – Thread life is increased as thread friction is virtually eliminated, which becomes valuable in applications requiring repeated assembly and disassembly. Surface coatings are available for applications involving severe corrosive and extreme temperature conditions.

4. Minimize space and weight – Lighter and less expensive than other thread inserts, these wiry fellows can be incorporated into existing designs, often allowing the use of thinner or lighter parent materials.

5. Convert threads from Metric/Inch – Rather than replace all your hardware, taps and dies, you can use Wire inserts to convert threads and use your existing hardware and tools.

Lesson Learned, considerations when selecting and using Wire Inserts

  • Inserts are easy to install! You can use standard drill bits and plug taps to drill and tap the hole.
  • For high volume installations, consider strip feed inserts or use automatic or air-driven installation tools.
  • Inserts often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series include MS122076 thru MS122275, NAS1130, MS124651 thru 124850, MS21208, MS21209, MS122076, MS33537, MA3279, MA3329, NA0276.
  • Wire inserts are sometimes referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Helicoil, Kato, Keensert and EZ Lok.
  • Materials available include 18-8 stainless steel, phosphor bronze, X 750 Inconel, 316 Stainless steel and inserts may be lubricated or dry filmed to offer easy threading and corrosion protection.
Wire Inserts Available at MF Supply

Here at MF Supply, we supply some of the most common and unusual Wire inserts, including:

  • The full range of commercial and mil-spec parts
  • Products kits including single and multiple sizes
  • Specials including Giant metric, 8-pitch kits, left hand kits and special lengths and diameters
  • We are authorized distributors for Chrislynn and E-Z Lok

For more detailed information on Wire inserts, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1821

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

About MF Supply
For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

§ Phone: 888-972-7397 [888-9-SCREWS]

§ Email: sales@mfsupply.com

§ Online: www.mfsupply.com

You are receiving this newsletter because you indicated interest in hearing from MF Supply. To remove yourself from this distribution list, please email us at sales@mfsupply.com with the word “REMOVE” in the subject line.


What the heck is Mil-spec DFARS?

MS24693C

Welcome to the second edition of our “What the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. If you sell to the military either directly or indirectly, then you are probably aware of today’s topic: “DFARS” and “Mil-spec fasteners”.

What does Mil-spec mean anyway?

Before we get into the nitty gritty of DFARS, let’s discuss what makes a “Mil-spec” fastener. Mil-spec is the informal name for the military standard the U.S. Department of Defense uses in the production of military equipment. For example, the MS24693C pictured above is a fastener produced according to military standards.

Mil-spec fasteners look a lot like their civilian cousins, but, these little guys are made to a specific standard that defines in detail, the screw’s attributes, including: dimensions, tensile strength, hardness, threads, drive type, material qualities and plating, just to name a few. Mil-spec fasteners are even traceable by lot to designated manufacturers. The government maintains a list of factories and suppliers who are qualified to manufacture and distribute Mil-spec fasteners. These suppliers have met all the government’s requirements and pass the highest quality control standards. This designation is called Qualified Suppliers List for Distributors [QSLD] and the Qualified Suppliers List for Manufacturer’s [QSLM].

AKA – Also known as…..

Mil-spec fasteners are usually designated by an AN, MS, NAS or NASM prefix followed by a part number. Each of these prefixes is an abbreviation: NAS stands for National Aerospace Standard and MS stands for Military Standard. An example of one of the most common and popular Mil-spec machine screws is the MS24693C. Its commercial equivalent is a Phillips Flat 100 degree Machine Screw in 300 series stainless steel. Below, we’ll tell you more about this popular fellow.

Who uses Mil-spec Fasteners?

Mil-spec fasteners are used by anyone manufacturing or servicing military equipment. Often, the bill of materials calls for specific Mil-spec grade fasteners in accordance with a part number, drawing or procurement requirement. Some of the most common uses of Mil-spec fasteners include aerospace and naval vessels.

Now, tell me about DFARS…

Almost a decade ago, the term “DFARS Compliant Material” came to the forefront for companies supplying parts and services to the government. The original Federal Acquisition Regulation (FAR) clause 252.225-7014 specified “A Preference for Domestic Specialty Metals.” What that means in our world is that for fasteners to be DFARS compliant, the metal used to fabricate them must be melted or manufactured in the United States or a qualifying country.

Qualifying countries include: Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Egypt, Finland, France, Germany, Greece, Israel, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, Turkey, United Kingdom of Great Britain and Northern Ireland.

Important Note: DFARS only pertains to fasteners made from “specialty metals” including: stainless steel, high alloy steel like Grade-BD, or Grade 5 Chromium steel with high chromium content.

To keep up to date with DFARs requirements, visit www.acq.osd.mil/dpap/dars/dfarspgi/current/index.html

section 252.225

An example of a DFARS Mil-Spec Screw please!

As we’ve learned, the MS24693C is actually Phillips Flat 100 degree Machine screws in 300 series stainless steel. The MS24693-C4 is a 4-40 x 3/8 Phillips Flat 100 Degree Machine Screw in 302 Stainless Steel, and it is one of the most widely used sizes. Interestingly, the MS24693C superseded the AN662C series, so you might come across the AN662C on an older print of bill of materials. Keep in mind, with any design or manufacturing decision, the reason for using a specific screw generally rests in the hands of engineering.

Features of the MS24693C

– Strict military standards ensure performance and reliability

– Made/melted in the USA or other DFARs-approved country

– Materials and dimensions meet Federal standard FF-S-92

– Inspected per Mil-I-45208

– Full lot traceability, manufacturer’s certification and chemical and physical certification

– Available in diameters from #0 through 1/4 inch in coarse and fine thread and various lengths

Lessons Learned: Considerations when purchasing MS24693C or other Mil-spec DFARs fasteners

  • Always ask for “full certifications”. This includes part name, part description, date of manufacture, lot number, chemical composition of material, and treatment of material including plating or passivation.
  • At point of purchase, make sure the screws are DFARS. If you do not specifically ask for DFARS-compliant screws, you might receive screws that don’t meet the DFARS requirements, in which case, they won’t meet military standards. We’ve learned this the hard way so hopefully you don’t have to!

MS24693C and other Mil-spec DFARS Fasteners in Stock at MF Supply

Here at MF Supply, we stock some of the most common Mil-spec Fasteners, including the following: Machine Screws, Socket Screws, Hex Head Cap screws, Nuts, Flat washers and Standoffs and Spacers.

Visit us at www.mfsupply.com/v/vspfiles/assets/images/MFSUPPLY_MILITARY.pdffor our military linecard.

For more detailed information on Mil-spec Fasteners, visit us at www.mfsupply.com/SearchResults.asp?Cat=1823

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

About MF Supply
For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

– Phone: 888-972-7397 [888-9-SCREWS]

– Email: sales@mfsupply.com

– Online: www.mfsupply.com

You are receiving this newsletter because you indicated interest in MF Supply. To remove yourself from this distribution list, please email us at sales@mfsupply.com with the word “REMOVE” in the subject line.


What the heck is a Cage Nut?

Posted: May 16, 2012

Author: Robin Lieberman

What the heck is that?

Welcome to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to a fastener made of two pieces – this little guy is called the Cage Nut.

What the heck is a Cage Nut?

A Cage Nut contains a free floating threaded square Nut retained within a spring steel cage. The spring steel cage has two Mounting legs or wings that, when pressed together, allow the nut to clip into the square hole and lock the fastener in place within the rack hole.

Who uses Cage Nuts?

Cage Nuts are commonly used to mount lighting systems, electrical equipment or instruments onto rail racks. The Cage Nut clips into the rack’s square mounting hole and usually positions the Nut toward the inside of the rack. The Nut is typically loose or “floating” in the Cage to allow for adjustments when installing the screw. This configuration allows flexibility in mounting and assembling components.

AKA – Also know as…..

Cage Nut is a funny little guy and answers to a bunch of different names – some of Cage Nut’s favorite aliases are: Grip Nuts, Retainer Nuts, Rack Nuts or Floating Nuts. Lots of monikers!

Advantages of Cage Nuts

  • Snap directly into square rack holes
  • Easily installed with no special tools or skills, eliminating the need for special operations
  • The Nut floats within the spring-steel cage which offsets normal hole misalignment
  • Can be easily popped out and replaced
  • Ideal when removal or installation of rack components might cause holes to strip
  • Combines flexibility of spring steel cage with the strength of a threaded nut

Lessons learned- Considerations when selecting Cage Nuts

  • I always recommend purchasing the corresponding screw to go with the Cage Nuts (i.e. buy the 3/8-16 Cage Nuts together with the 3/8-16 screws). This prevents you from selecting the wrong size Cage Nut. To be 100% sure, you should do a quick test to make sure the screws and Cage Nuts fit together before beginning the installation process.
  • When it comes to installation, Cage Nuts can be tough on your fingers when trying to install or uninstall them with your bare hands. Consider using a Cage Nut Tool.
  • Sizing is based on 3 components: The screw thread, panel thickness and mounting hole. Double check your measurements before you make your purchase.

Cage Nuts in Stock at MF Supply

Here at MF Supply, we stock some of the most common Cage Nuts, including:

  • From imperial size 6-32 up to ½-13
  • Metric M5 and M6
  • Stainless Steel
  • Steel zinc plated
  • Tinnerman alternatives

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

For more detailed information on Cage Nuts, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1851.

About MF Supply

For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

  • Phone: 888-972-7397 [888-9-SCREWS]
  • Email: sales@mfsupply.com
  • Online: www.mfsupply.com

Cage Nut

Cage Nut

Cage Nuts!


What the heck are Precision Shoulder Screws?

Newsletter

Volume 8

July 23, 2014

What the heck are Precision Shoulder Screws?

Here we go again, with our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Shoulder Screw.

What is a Precision Shoulder Screw?

Shoulder Screws, which are sometimes called Shoulder Bolts or Stripper Bolts, are (generally) hex socket screws with an enlarged, unthreaded cylindrical shoulder under the head. They are comprised of 3 main parts: the head, the shoulder and the thread. They come in two basic categories, “Commercial” and “Precision”.

Commercial Shoulder Screws are made to inch standard ANSI ASME B18.8.2. The size range for the shoulder diameter is from ¼ to 2”. The thread class is 3A and the tolerance on the shoulder is +.005 / -.005.

Precision Shoulder screws are sometimes referred to as “tight tolerance” shoulder screws. They are not governed by any official ANSI or ASME standard. The size range for the shoulder diameter is from 3/32 to ½. The thread class is 2A and the tolerance on the shoulder diameter varies from +.000/-.001 to -.0005 to -.0015 depending upon the manufacturer. Now that’s precise!

Who uses Shoulder Screws?

Just as Dowel Pins and Retaining Rings are used to locate or hold parts together within a precision assembly or a fixture, so are Precision Shoulder Screws.

Yet shoulder screws are more versatile. When installed, the unthreaded shoulder acts as a shaft for rotating items such as bearings and bushings, precision spacing, machinery support, and motion guiding. Precision Shoulder screws exacting tolerances make them ideal for use with other precision components.

They are broadly used across various applications in many industries, including: aerospace, electrical motors, hydraulic equipment, instrumentation, tooling and fixtures, machinery, military and many more.

What do I need to consider when selecting Shoulder Screws?

Although Shoulder Screws are offered in a multitude of materials and styles, when it comes to the main commercial and precision offerings, there are a few main issues to consider.

Which Drive and Head Style?

Precision shoulder screws are readily available in hex socket and slotted drives. Philips drives are available in certain sizes. Torx and Star are available for special order. Typical head styles are a modified fillister with a flat top where the head diameter is about twice the head height. Low head fillisters are available in certain sizes

Which material do I need?

Precision shoulder bolts are readily available in Type 18-8/303 Stainless Steel and 416 Stainless Steel. 316 Stainless Steel, Alloy and other exotic materials are available for special order.

Are there other factors to consider?

When ordering Precision Shoulder screws, specify the Shoulder Diameter, Shoulder length, thread size, material and drive type. For example, an example of a typical Precision Shoulder screw is a ¼ shoulder x ½ long x 10-32 thread in SS18-8 with a hex-socket drive. Non-locking is the most popular style, but locking may also be available.

Precision Shoulder Bolts often show up under their brand name. Some of the most popular brands include: BERG, Concord, Globe, PIC, Lyn-tron and RAF. A comprehensive selection of Shoulder Screws is also offered by McMaster-Carr (tight tolerance series), MSC and Grainger.

Finally, Precision Shoulder Screws can also show up under their Mil-spec numbers, which include MS51575 & MS51576 and are DFARS compliant with full paperwork.

Precision Shoulder Screws at MF Supply

We offer:

The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.

Brand names and generic equivalents.

Custom made parts per print in non-standard and exotic materials and finishes.

Inch and Metric sizes.

For more detailed information on Precision Shoulder Screws, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1922

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!


What the heck are Dowel Pins?

Dowel Pins

Welcome back to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Dowel Pin.

What is a Dowel Pin?

If you have ever shopped at Ikea or assembled furniture on your own, then you are familiar with the peg shaped non-threaded wooden pins that are used to join parts together, aka as a Dowel Pin.

For the purposes of manufacturing, Dowel Pins are solid, headless cylindrical shaped straight metal pins with a centerless ground finish. Typically hardened and manufactured to precise fractional diameters and lengths, Dowel Pins come in a variety of sizes, styles, designs and materials that cause confusion among buyers, engineers and end-users alike! Today, we will try simplify this confusing category of fasteners.

Who uses Dowel Pins?

Dowel Pins are used as a hinge, shaft or pivot to locate or hold parts together within a precision assembly or a fixture.

They are broadly used across various applications in many industries, including: aerospace, electrical motors, hydraulic equipment, instrumentation, tooling and fixtures, machinery, military and many more.

Dowel Pins are popular within assemblies since they can withstand frequent insertion and removal without distortion. And production favors pins since they require no extra fastening hardware for insertion, no secondary operations and no mating parts. All this adds up to speedier production, which makes everyone in the food chain happy!

What do I need to consider when selecting Dowel Pins?

Although Dowel Pins are offered in a multitude of materials and styles, when it comes to the main commercial and Mil-spec offerings, there are a few main issues to consider.

Standard, Oversized or Undersized?

Standard series Dowel Pins are used for initial applications. They have a basic diameter 0.0002 inch over the nominal diameter. For example, a ¼ standard dowel will have a diameter between .2501-.2503.

Oversized series Dowel Pins are usually used to fit into worn holes and are generally used in the aftermarket for repairs. They have a basic diameter 0.001 inch over the nominal diameter. For example, a ¼ oversized dowel will have a diameter between .2509-.2511.

Undersized series Dowel Pins are used for inconsistent holes. They have a basic diameter -0.0002 inch under the nominal diameter. For example, a ¼ undersized dowel will have a diameter between .2500-.2498. The Mil-P-21143/2- falls into the undersized category.

Chamfer or radius on the end?

In general, commercial pins are made to inch standard ANSI ASME B18.8.2. Standard alloy pins will have a radius on one end and a chamfer on the other end. However, stainless steel Dowel Pins are often manufactured with a chamfer on both ends.

Commercial or Military?

If you or your customer needs domestically made, DFARs pins to the most exacting standards, then military may be the right pin for you!

Alloy or stainless? And which stainless for that matter?

Alloy Steel is the strongest pin available and is hardened. It can be finished with Black Oxide to provide greater rust resistance than plain alloy.

Type 416 Stainless steel is the strongest standard stainless steel offering, and is the material used for MS16555 and MS16556 series. Magnetic.

Type 18-8/303 Stainless Steel is the most commonly available stainless offered and is the standard material offered for Mil-P-21143 series.

Type 316 Stainless Steel is the most corrosion resistant stainless available and does not correlate to a Mil-spec part.

Are there other factors to consider?

Dowel Pins often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series for Dowel Pins include Mil-P-21143 (303 Stainless), MS16555 (standard series offered in both alloy and 416 Stainless Steel) and MS16556 (oversized series offered in both alloy and 416 stainless steel).

If you are not ordering by an MS or NAS Mil-Spec part number, then inch Dowel Pins conform to ANSI/ASME B18.8.2. For commercial pins, be mindful to specify the material and size tolerance that you need. Unless noted, Dowel Pins are precision ground, hardened and heat treated to meet the proper Rockwell hardness.

And remember, no hammers! When installing Dowel Pins, never drive the pin into the hole with force, always press it in for best results.

Dowel Pins at MF Supply

We offer:

The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.

Brand names and generic equivalents.

Custom made parts per print in non-standard and exotic materials and finishes.

Inch and Metric sizes including DIN 7, DIN 6325, and ISO 2338 and 8734

For more detailed information on Dowel Pins, visit us at http://www.mfsupply.com/dowel_pins_s/1925.htm


What the heck are Retaining Rings?

What the heck are Retaining Rings?

Retaining Rings

Welcome back to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Retaining Ring.

What is a Retaining Ring?
Retaining Rings are yet another way to position, locate and retain parts within an assembly. Shaped like an open ring and made of metal, Retaining Rings can be coiled from wire, stamped or laser cut. They come in a variety of styles and materials, each solving a unique fastening problem.

Generally, Retaining Rings work together with a bore or a shaft by snapping into a groove or being pushed into place to create a high strength shoulder to retain parts.

AKA – Also known as…..
The Retaining Ring is a funny little guy and answers to a bunch of different names – some of Retaining Ring’s favorite aliases are: snap rings, wire rings, circlips, retainer clips, spiral rings, wire clips, c-rings, grip rings, klip rings and push-on rings.

Who uses Retaining Rings?
Any application with a bore/housing or shaft that requires a shoulder to keep parts in place within an assembly is a candidate for using Retaining Rings.

Retaining Rings are broadly used across various applications in many industries, including: aerospace, drive shafts, electrical motors, hydraulic equipment, instrumentation, lighting assemblies, machinery, nuclear equipment and many more. Retaining Rings are very common in the automotive industry.

Why use a Retaining Ring vs. a screw or a bolt?
When a shaft or bore design that includes assembled components needs a shoulder, it can be costly to machine the shoulder, mate threaded components and fasteners together and drill and coordinate threaded holes and access holes to fasten the assembly. Retaining Rings can serve as a cost effective and time saving alternative.In addition to cost, Retaining Rings offer 2 special benefits a) they can be more resilient than screw assemblies in high vibration environments, b) they are made from less material, hence they are cleaner and gentler on the environment (aka Green!).

What styles are available?
Retaining Rings come in a variety of styles and materials. The most popular styles are: External (used on shafts), Internal (used for bores) and E-Style. The most popular materials are Carbon Spring Steel, PH15-7 Stainless Steel and Beryllium Copper. The most common finishes for Carbon Steel Rings are Phosphate, Zinc Clear and Zinc Yellow.

Are there other factors to consider?

  • As discussed, Retaining Rings are often referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Anderton, Rotor Clip, S&M and Waldes/Truarc. We can supply the brand name or generic alternatives. Note: Currently, Rotor Clip (Waldes/Truarc) and S&M are the only full-line USA manufacturers.
  • Retaining Rings often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series for Retaining Rings include: MS16624, MS16625, MS16626, MS16627, MS16628, MS16629, MS16630, MS16631, MS16632, MS16633, MS3215, MS3217 and MS90707.
  • Sizes available vary based on the style. The general range is from 1/16 to 10″. Metric sizes are also available.

Retaining Rings at MF Supply

We offer:

  • The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.
  • Brand names and generic equivalents.
  • Custom made parts per print.
For more detailed information on Retaining Rings, visit us at
And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

What the heck is a Keensert® Key-locking insert?

What the heck is a Keensert® Key-locking insert?

Image

Key-locking insert

We close out the first quarter of 2013 by introducing you to the Keensert Key-locking insert. Like its relative, the Helical wire insert, (see January 2013), the Key-locking insert was originally designed to repair parts with damaged threads.

What is a Keensert Key-locking insert?

The Key-locking threaded insert is a solid bushing style insert that is threaded on both the inside and the outside, and has wedges or “keys” attached to the top of the insert. Keensert® is the registered trademark for one of the most popular brand names for this part and is used commonly to describe this insert.

Who uses Key-locking inserts?

Generally, Key-locking inserts are used to distribute loads and strengthen or repair threads against failures due to stripping, seizing or corrosion. Key-locking inserts are commonly used in high torque and high temperature situations, and in applications where fasteners may be repeatedly removed and reassembled.

Typical applications are transmission housings, electronic equipment and suspension units. Key-locking inserts are common in the aerospace industry.

Why use a Key-locking insert vs. a Helical wire insert?

There are three main differences between Key-locking inserts and Helical Wire Inserts: Key-locking inserts are stronger than helical wire inserts, they are easier to install than helicals, and they are more expensive!

In heavy wear, high vibration and high heat situations where saving space is not a concern and hole depth is limited, Key-locking inserts are the best bet. Their “keys”, which are driven down into the tapped threads, provide a mechanical lock against rotation, especially when the mating stud or bolt will be removed frequently.

When reducing costs and minimizing space are priorities, helical wire inserts are the way to go. They are particularly useful for creating permanent strong threads in softer materials such as aluminum, titanium and magnesium alloys, and are best suited to lower heat and lower torque environments.

What styles are available?

Key-locking inserts come in four main styles: Miniature, Thin Wall, Heavy Duty Wall (general purpose) and Extra Heavy Duty. Inserts can be locking or non-locking.

Miniature Key-locking inserts are used in electronic and aerospace applications where size and strength are critical. These inserts may be installed in sheet material as thin as 1/16″.

Thinwall inserts have smaller external threads than standard heavy-duty inserts and are ideal for tight spaces where less pull-out strength is acceptable.

General-purpose Heavy Duty inserts have a thick, heavy-duty thread wall, suitable for most applications.

Extra-heavy duty inserts are used in oversized and overly worn holes.

Installation is 5 easy steps!

1) Drill with a standard tap drill and countersink with a standard 82° – 100° countersink (90° for Miniature Inserts). Note: Drill is oversize see charts for proper dimensions.

2) Tap new threads with a standard tap.

3) Screw in the insert until it is .010-.030 (.005-.015 for Miniature Inserts) below the surface. Keys locate the proper depth.

4) Drive keys down with several hammer taps on the proper installation tool.

5) You are done!

Considerations for selecting and using Key-locking inserts.

  • Inserts often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series for Key-locking inserts include: MS5180, MS51831, MS51832, NAS1394, NAS1395, NA0146, NA0147, NA0148, NA0149, NA150, NA0151.
  • As discussed, Key-locking inserts are often referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Alcoa, Fairchild, Keensert and Tridair.
  • Materials available include Carbon steel, Stainless Steel, Alloy 4140 and A286.
  • Diameters available: American – #6 to 1 1/2 ” and Metric – M4 to M24
Key-locking inserts at MF SupplyWe offer:

  • The full range of commercial and mil-spec parts
  • Products kits including single and multiple sizes
  • We are authorized distributors for Chrislynn and E-Z Lok

For more detailed information on Key-locking insert, visit us at http://www.mfsupply.com/Keensert_Style_Inserts_s/1864.htm

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!


What the heck is a Wire Insert?

Image

Today, we will introduce you to the Wire insert which was originally designed to repair parts with damaged threads, but has evolved for use in a variety of applications that save time and money and improve product reliability. Do we have your attention? Great, then read on…

What is a Wire Insert?

Wire inserts are precision-formed continuous wire coils that provide permanent, wear-resistant threads which exceed the strength of the parent material. Often underestimated, the popular misconception is that Wire inserts are intended solely for thread repair, when, in fact, they have other significant uses discussed in the next section. Not to be confused with other types of solid inserts or rivnuts, Wire inserts resemble springs and are sometimes referred to as “helicals”.

Who uses Wire Inserts?

Wire inserts are used for 3 main reasons: 1) to repair damaged threads in parts that would otherwise have to be scrapped; 2) to strengthen threads against failures due to stripping, seizing or corrosion; 3) to convert threads between inch and metric sizes. We told you they were versatile!

What styles are available?

Wire inserts come in 2 main styles: tang and tangless.

The original and widely used tang style has a prong at one end to facilitate installation. The newer tangless style is becoming popular since this style had no prongs to break off, retrieve, or lose and is easily adjusted or removed after installation. Tangless inserts are commonly used in electronic applications where loose tangs might cause damage.

Wire Inserts can be free-running or locking.

Free running is the most common style used for thread repair. The “free” diameter of the insert is larger than the installed diameter and this configuration generates balanced pressure distribution between the coils and threads.

Locking style inserts are recommended for applications that require constant torque, or are subject to stress or vibration. The locking style features a crimped turn that acts as a locking mechanism that grips the bolt or screw to prevent loosening from vibration, eliminating the need for lock wiring, lock-nuts, lockwashers, pellets/patches or other thread locking devices.

A third commonly used insert that deserves an honorable mention is a K-type Insert. Sometimes called by the brand Keensert, these externally threaded solid style inserts can be used in almost any material: aluminum, magnesium, cast iron, carbon steel, stainless steel and plastic. K-type inserts have locking “keys” that provide a mechanical lock, and are commonly used in heavy wear and high vibration situations.

5 Features & Benefits of Wire Inserts

1. Repair rather than scrap parts – Wire inserts remain the most cost effective, efficient and fastest method to repair damaged threads.

2. Stronger Assemblies – The flexibility of the insert provides a more balanced load distribution, practically eliminating thread erosion and providing better stress allocation, even in low strength materials.

3. Wear and Corrosion Resistance – Thread life is increased as thread friction is virtually eliminated, which becomes valuable in applications requiring repeated assembly and disassembly. Surface coatings are available for applications involving severe corrosive and extreme temperature conditions.

4. Minimize space and weight – Lighter and less expensive than other thread inserts, these wiry fellows can be incorporated into existing designs, often allowing the use of thinner or lighter parent materials.

5. Convert threads from Metric/Inch – Rather than replace all your hardware, taps and dies, you can use Wire inserts to convert threads and use your existing hardware and tools.

Lesson Learned, considerations when selecting and using Wire Inserts

  • Inserts are easy to install! You can use standard drill bits and plug taps to drill and tap the hole.
  • For high volume installations, consider strip feed inserts or use automatic or air-driven installation tools.
  • Inserts often show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series include MS122076 thru MS122275, NAS1130, MS124651 thru 124850, MS21208, MS21209, MS122076, MS33537, MA3279, MA3329, NA0276.
  • Wire inserts are sometimes referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Helicoil, Kato, Keensert and EZ Lok.
  • Materials available include 18-8 stainless steel, phosphor bronze, X 750 Inconel, 316 Stainless steel and inserts may be lubricated or dry filmed to offer easy threading and corrosion protection.
Wire Inserts Available at MF Supply

Here at MF Supply, we supply some of the most common and unusual Wire inserts, including:

  • The full range of commercial and mil-spec parts
  • Products kits including single and multiple sizes
  • Specials including Giant metric, 8-pitch kits, left hand kits and special lengths and diameters
  • We are authorized distributors for Chrislynn and E-Z Lok

For more detailed information on Wire inserts, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1821

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

About MF Supply
For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

§ Phone: 888-972-7397 [888-9-SCREWS]

§ Email: sales@mfsupply.com

§ Online: www.mfsupply.com

You are receiving this newsletter because you indicated interest in hearing from MF Supply. To remove yourself from this distribution list, please email us at sales@mfsupply.com with the word “REMOVE” in the subject line.


What the heck is Mil-spec DFARS?

MS24693C

Welcome to the second edition of our “What the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. If you sell to the military either directly or indirectly, then you are probably aware of today’s topic: “DFARS” and “Mil-spec fasteners”.

What does Mil-spec mean anyway?

Before we get into the nitty gritty of DFARS, let’s discuss what makes a “Mil-spec” fastener. Mil-spec is the informal name for the military standard the U.S. Department of Defense uses in the production of military equipment. For example, the MS24693C pictured above is a fastener produced according to military standards.

Mil-spec fasteners look a lot like their civilian cousins, but, these little guys are made to a specific standard that defines in detail, the screw’s attributes, including: dimensions, tensile strength, hardness, threads, drive type, material qualities and plating, just to name a few. Mil-spec fasteners are even traceable by lot to designated manufacturers. The government maintains a list of factories and suppliers who are qualified to manufacture and distribute Mil-spec fasteners. These suppliers have met all the government’s requirements and pass the highest quality control standards. This designation is called Qualified Suppliers List for Distributors [QSLD] and the Qualified Suppliers List for Manufacturer’s [QSLM].

AKA – Also known as…..

Mil-spec fasteners are usually designated by an AN, MS, NAS or NASM prefix followed by a part number. Each of these prefixes is an abbreviation: NAS stands for National Aerospace Standard and MS stands for Military Standard. An example of one of the most common and popular Mil-spec machine screws is the MS24693C. Its commercial equivalent is a Phillips Flat 100 degree Machine Screw in 300 series stainless steel. Below, we’ll tell you more about this popular fellow.

Who uses Mil-spec Fasteners?

Mil-spec fasteners are used by anyone manufacturing or servicing military equipment. Often, the bill of materials calls for specific Mil-spec grade fasteners in accordance with a part number, drawing or procurement requirement. Some of the most common uses of Mil-spec fasteners include aerospace and naval vessels.

Now, tell me about DFARS…

Almost a decade ago, the term “DFARS Compliant Material” came to the forefront for companies supplying parts and services to the government. The original Federal Acquisition Regulation (FAR) clause 252.225-7014 specified “A Preference for Domestic Specialty Metals.” What that means in our world is that for fasteners to be DFARS compliant, the metal used to fabricate them must be melted or manufactured in the United States or a qualifying country.

Qualifying countries include: Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Egypt, Finland, France, Germany, Greece, Israel, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, Turkey, United Kingdom of Great Britain and Northern Ireland.

Important Note: DFARS only pertains to fasteners made from “specialty metals” including: stainless steel, high alloy steel like Grade-BD, or Grade 5 Chromium steel with high chromium content.

To keep up to date with DFARs requirements, visit www.acq.osd.mil/dpap/dars/dfarspgi/current/index.html

section 252.225

An example of a DFARS Mil-Spec Screw please!

As we’ve learned, the MS24693C is actually Phillips Flat 100 degree Machine screws in 300 series stainless steel. The MS24693-C4 is a 4-40 x 3/8 Phillips Flat 100 Degree Machine Screw in 302 Stainless Steel, and it is one of the most widely used sizes. Interestingly, the MS24693C superseded the AN662C series, so you might come across the AN662C on an older print of bill of materials. Keep in mind, with any design or manufacturing decision, the reason for using a specific screw generally rests in the hands of engineering.

Features of the MS24693C

– Strict military standards ensure performance and reliability

– Made/melted in the USA or other DFARs-approved country

– Materials and dimensions meet Federal standard FF-S-92

– Inspected per Mil-I-45208

– Full lot traceability, manufacturer’s certification and chemical and physical certification

– Available in diameters from #0 through 1/4 inch in coarse and fine thread and various lengths

Lessons Learned: Considerations when purchasing MS24693C or other Mil-spec DFARs fasteners

  • Always ask for “full certifications”. This includes part name, part description, date of manufacture, lot number, chemical composition of material, and treatment of material including plating or passivation.
  • At point of purchase, make sure the screws are DFARS. If you do not specifically ask for DFARS-compliant screws, you might receive screws that don’t meet the DFARS requirements, in which case, they won’t meet military standards. We’ve learned this the hard way so hopefully you don’t have to!

MS24693C and other Mil-spec DFARS Fasteners in Stock at MF Supply

Here at MF Supply, we stock some of the most common Mil-spec Fasteners, including the following: Machine Screws, Socket Screws, Hex Head Cap screws, Nuts, Flat washers and Standoffs and Spacers.

Visit us at www.mfsupply.com/v/vspfiles/assets/images/MFSUPPLY_MILITARY.pdffor our military linecard.

For more detailed information on Mil-spec Fasteners, visit us at www.mfsupply.com/SearchResults.asp?Cat=1823

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

About MF Supply
For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

– Phone: 888-972-7397 [888-9-SCREWS]

– Email: sales@mfsupply.com

– Online: www.mfsupply.com

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What the heck is a Cage Nut?

Posted: May 16, 2012

Author: Robin Lieberman

What the heck is that?

Welcome to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to a fastener made of two pieces – this little guy is called the Cage Nut.

What the heck is a Cage Nut?

A Cage Nut contains a free floating threaded square Nut retained within a spring steel cage. The spring steel cage has two Mounting legs or wings that, when pressed together, allow the nut to clip into the square hole and lock the fastener in place within the rack hole.

Who uses Cage Nuts?

Cage Nuts are commonly used to mount lighting systems, electrical equipment or instruments onto rail racks. The Cage Nut clips into the rack’s square mounting hole and usually positions the Nut toward the inside of the rack. The Nut is typically loose or “floating” in the Cage to allow for adjustments when installing the screw. This configuration allows flexibility in mounting and assembling components.

AKA – Also know as…..

Cage Nut is a funny little guy and answers to a bunch of different names – some of Cage Nut’s favorite aliases are: Grip Nuts, Retainer Nuts, Rack Nuts or Floating Nuts. Lots of monikers!

Advantages of Cage Nuts

  • Snap directly into square rack holes
  • Easily installed with no special tools or skills, eliminating the need for special operations
  • The Nut floats within the spring-steel cage which offsets normal hole misalignment
  • Can be easily popped out and replaced
  • Ideal when removal or installation of rack components might cause holes to strip
  • Combines flexibility of spring steel cage with the strength of a threaded nut

Lessons learned- Considerations when selecting Cage Nuts

  • I always recommend purchasing the corresponding screw to go with the Cage Nuts (i.e. buy the 3/8-16 Cage Nuts together with the 3/8-16 screws). This prevents you from selecting the wrong size Cage Nut. To be 100% sure, you should do a quick test to make sure the screws and Cage Nuts fit together before beginning the installation process.
  • When it comes to installation, Cage Nuts can be tough on your fingers when trying to install or uninstall them with your bare hands. Consider using a Cage Nut Tool.
  • Sizing is based on 3 components: The screw thread, panel thickness and mounting hole. Double check your measurements before you make your purchase.

Cage Nuts in Stock at MF Supply

Here at MF Supply, we stock some of the most common Cage Nuts, including:

  • From imperial size 6-32 up to ½-13
  • Metric M5 and M6
  • Stainless Steel
  • Steel zinc plated
  • Tinnerman alternatives

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

For more detailed information on Cage Nuts, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1851.

About MF Supply

For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

  • Phone: 888-972-7397 [888-9-SCREWS]
  • Email: sales@mfsupply.com
  • Online: www.mfsupply.com

Cage Nut

Cage Nut

Cage Nuts!