Precision Shoulder Screws!? What the heck are those?
Posted: April 26, 2023 Filed under: DFARS, Mil-Spec, MS51575, MS51576, Precision Shoulder Screws | Tags: Fasteners, hex socket screws, MS51575, MS51576, Precision Shoulder Screws, Shoulder Bolts, Stripper Bolts Leave a comment
What the heck are Precision Shoulder Screws?
Here we go again, with our “what the heck is that” series refreshed for 2023, 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 re-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 currently offer:
- The full range of commercial and mil-spec parts, including parts that are DFARS and ROHS compliant.
- MS51576 Now available for online purchase!
- Brand names and generic equivalents.
- Custom made parts per print in non-standard and exotic materials and finishes.
- Inch, Metric and Mil-Spec sizes.
For more detailed information on Precision Shoulder Screws, visit us at our website or Request a Quote today, and our MF Supply team of sourcing experts can help you find what you need. “Finding the right screw for you” is our tag line after all!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
Mil-Spec DFARS!? What the heck is that?
Posted: March 14, 2023 Filed under: DFARS, Fasteners, Mil-Spec, Military Standard, MS24693C | Tags: What the heck is Mi-Spec DFARS? Leave a comment
Welcome to the second edition of our “What the heck is that” series, refreshed for 2023, 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 strict military standards that are maintained by the DLA (Defense Logistics Agency). (https://www.dla.mil/) INSERT THIS LINK I DONT KNOW HOW
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 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].
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 may be 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, naval vessels and weapons systems.
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.
Visit the DPC website, section 252.225, to keep up to date with DFARs requirements, which were updated January 2023. Click here: https://www.acq.osd.mil/dpap/dars/dfars/html/current/252225.htm.
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 directly from the manufacturer.
- When purchasing Specialty metal screws that qualify for DFARS, 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!
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. Checkout our instock Military Line of fasteners. (LINK HERE https://www.mfsupply.com/mil-spec-fasteners-s/1823.htm) . If you don’t what you need listed, send us an RFQ, as we are sourcing experts!
Visit our website for more detailed information on Mil-spec Fasteners. Also, checkout our military linecard!
And, as always, if you don’t see it listed, ask us. “Finding the right screw for you” is our tag line after all!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
Buyer’s Guide to Metric Dowel Pins Refreshed for 2023!
Posted: February 28, 2023 Filed under: DIN 6325, DIN 7, dowel pin, ISO 2338, ISO 8734, Metric Dowel Pins, Mil-Spec, PRECISION DOWEL PIN Leave a comment
7 Things to Know When Buying Metric Dowel Pins
This guide is a follow up to our Dowel Pin Buyer’s Guide published last week, on February 23, 2023. 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:
- 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.
- 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?
- DIN 7
- DIN 6325 & DIN 6325H
- ISO 2338A & ISO 2338B
- ISO 8734
- PRECISION UNHARDENED PRESS FIT DOWEL PINS SS303
- PRECISION HARDENED DOWEL PINS SS416
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 |
DIN7ISO 2338ISO 2338A |
Rounded or beveled |
Steel (least common)300 Series Stainless Steel includingA1=18-8, 303, 304A4=316 |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M.8-M20 |
ISO 2338B |
Rounded or beveled |
300 Series Stainless SteelA1=18-8, 303, 304 |
H8 diameter tolerance |
Unhardened |
M1.5-10 |
DIN 6325DIN 6325HISO 8734AISO 8734 |
Rounded on one endBeveled on one end |
Alloy Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 52-62 |
M1-M25 |
Precision Unhardened |
Rounded |
300 Series Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M1-M12 |
Precision Hardened |
Rounded on one endBeveled on one end |
416 Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 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.
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
The Buyer’s Guide to Dowel Pins You Must Have Today! Updated for 2023!
Posted: February 23, 2023 Filed under: dowel pin, Mil-Spec, MS16555, MS16556 and Mil-P-21143., PRECISION DOWEL PIN 1 Comment
MF Supply is a trusted Supplier of Precision Dowel Pins for manufacturers. Through our extensive assortment of Inch, Metric, Commercial, Mil-Spec and OEM brand names and equivalents, we offer our customers quality imported and domestic dowel options. Our products are competitively priced with fast delivery from multiple distributions centers across the USA. Our goal is to help simplify the buying process for this sometimes complex and confusing category of fasteners.
8 Things to Know When Buying Dowel Pins
If you are a manufacturer working with complex assemblies or fixtures, then you’re likely very familiar with precision dowel pins. Commonly used as a hinge, shaft or pivot to locate or hold assembled parts together, dowel pins can withstand frequent insertion and removal without distortion. 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.
Our goal is to help simplify the buying process for this sometimes complex and confusing category of fasteners.
1. What is a precision dowel pin?
Dowel pins are solid, headless cylindrical shaped straight metal pins with a centerless ground finish. Manufactured to precise fractional diameters and lengths, dowel pins come in a variety of sizes, styles, designs and materials. This variability can cause confusion among buyers, engineers and end-users alike.
2. What materials and platings are available?
Precision dowel pins are available off the shelf in alloy steel (typically hardened) and stainless steel grades 18-8/303, 316 and 416 (typically hardened). Other exotic materials or special finishes are available for special order with a lead time.
3. What sizes are available?
Standard sizes include inch from 1/16″ to 1″ diameter, and metric from M1 to M20 diameter. Length options vary by diameter. Other diameters and special lengths are available for special order and usually involve a lead time.
4. When ordering, do I need to specify the dowel pin tolerance or call out attributes such as standard, undersized or oversized fit?
Precision dowel pins often show up under their MIL-SPEC numbers, MS16555, MS16556 and Mil-P-21143. Metric dowel pins might show up under the following DINs and ISO numbers: DIN 7, DIN 6325, and ISO 2338 and 8734. Dowel pins might also show up under a manufacturer part number such as Pic, WM Berg, Unbrako or Holo-Krome.
If you are ordering by MIL-SPEC, manufacturer’s part number or DIN, then the general attributes including tolerance and style are known. Here are a few of the other options that will help you order the correct pin:
- The most common standard inch or imperial sized precision dowel pin is made to the ASME ANSI B18.8.2 spec and has a diameter tolerance of -0.00 / +0.0002 and length tolerance of +/-0.010. For example, a ¼” (0.25) diameter standard dowel pin will have a diameter between 0.2500–0.2502″.
- The standard metric tolerance is related to the DIN. Both DIN 7 and DIN 6325 have a standard m6 diameter tolerance of +0.012mm / +0.004mm and a length tolerance related to the specific pin length.
- Undersized series dowel pins are used for inconsistent holes. They have a basic diameter 0.0002″ under the nominal diameter. For example, a ¼” (0.25) diameter undersized dowel pin will have a diameter between 0.2500–0.2498″. The Mil-P-21143/2- falls into the undersized category.
- Important note: All pin options may not be available in all sizes and materials.
- OEM branded pins have their own tolerances and specifications.
- Finally, the Oversized series of dowel pins are usually used to fit into worn holes and are generally used in the aftermarket for repairs. These pins are only available off the shelf in steel in a small range of sizes.
5. Can I specify if I need radius or chamfer 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 or a radius on one end and a chamfer on the other end. Specific style requirements are available for special order and usually involve a lead time.
6. What information do I need to request a quote?
The easiest way to order is by either the manufacturer or MIL-SPEC part number. To order by description, you need the diameter, length and material and if applicable, and any special tolerance, plating or style requirements.
7. Do I need to buy special installation tools?
Just remember, no hammers! When installing dowel pins, never drive the pin into the hole with force. Always press it in for best results. And production favors pins since they require no extra fastening hardware for insertion, no secondary operations, and no mating parts. This ease-of-use adds up to speedier production, which makes everyone in the food chain happy!
8. 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 and might have an additional fee.
Available Dowel Pins Categories
We are Dowel Pin experts, offering the full catalog of standard Dowel Pins in Inch, Metric, Military and OEM branded options in a wide selection of materials, sizes and specifications. As stocking distributors, many dowel pins are available and ready to ship today from our national distribution centers.
- The full range of commercial and MIL-SPEC parts (M21143, MS16555, MS9390), including parts that are USA made, DFARS and ROHS compliant.
- Inch sizes to ASME ANSI B18.8.2 standards in Alloy Steel, Stainless Steel 18-8, 316, 400 Series and Hardened
- Metric sizes including DIN 7, DIN 6325, and ISO 2338 and 8734 in Alloy Steel, A2 & A4 Stainless Steel
- Precision Series and OEM branded equivalents to PIC, BERG, both Inch & Metric Precision Dowel pins including Press-Fit A, B and Slip-Fit C series and all MD series pins in 416 and 303 Stainless Steel.
In addition to our vast selections of standards, we offer Custom-made parts per print in non-standard sizes and exotic materials and finishes made here in the USA with full certifications. Minimums and lead times will apply.
Seeking parts not listed for purchase on our website? We’ve got you covered! Submit your Dowel Pin RFQ and our team of experts will return your quote quickly!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
Six Reasons To Buy From MF Supply
- Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online. We are adding items and improving functionality daily!
- Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers.
- Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
- Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
- One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
- WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
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Get the Job Done with a Pneumatic Power Tool
Posted: February 3, 2023 Filed under: keensert, KEENTOOLPNEUMATIC-RS, key-locking inserts, Mil-Spec, Pneumatic Power Tools | Tags: Hardware, Keenserts, KEENTOOLPNEUMATIC-RS, Key Locking Inserts, Mil-spec fasteners, Pneumatic Power Tools, Power Tool Leave a comment
Now introducing the Rock Solid Hydro-Pneumatic Key-locking Insert Installation Tool!
A single button is all it takes to operate this tool and to get the job done. No need to use a hammer and a drill to drive the key locking insert into place.
Don’t know what a pneumatic power tool is or how to use one? Read on!
What is a pneumatic power tool?
Pneumatic tools are designed to speed up the installation process of key locking inserts—also known as keenserts. They provide you with increased precision and control, improved torqueing, reduced vibration and noise, and more versatility for your projects.
How do I use a pneumatic power tool?
Using a pneumatic power tool is very simple and bound to give you some peace of mind in the process! To use a pneumatic power tool, simply set up or prepare the material to be used in the key locking insert (Keensert) installation process and:
- Drill and countersink the material.
- Tap the hole in the material.
- Insert the key locking insert (Keensert) into the hole.
- Screw the key locking insert down into the material with the aid of the pneumatic power tool!
Keensert Installation Tool Kit
We offer the pneumatic power tool you need to quickly assemble your key locking inserts. Check them out here. Request a quote today, and our team of experts can help source your needs!
Do you need more details on why you need a pneumatic power tool? Watch the video below!
Optionally, you might also be interested on reading our previous blog posts about pneumatic power tools, and on how to manually install key locking inserts (Keenserts)!
Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.
The Buyer’s Guide to Dowel Pins You Must Have Today!
Posted: August 26, 2022 Filed under: dowel pin, Mil-Spec, MS16555, MS16556 and Mil-P-21143., PRECISION DOWEL PIN Leave a commentMF Supply is a trusted Supplier of Precision Dowel Pins to manufacturers with our extensive assortment of Inch, Metric, Commercial, Mil-Spec and OEM brand names and equivalents.
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What the heck is Mil-spec DFARS? 2019
Posted: July 29, 2019 Filed under: DFARS, Dodd-Frank, Domestic Fasteners, Mil-Spec, Uncategorized | Tags: DFAR, Dodd-Frank, What the heck is Mi-Spec DFARS? Leave a comment
MS24693C
Welcome to our ongoing “What the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that precision 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. 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. 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 the Qualified Suppliers List for Manufacturer’s [QSLM].
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.
The Defense Federal Acquisition Regulation Supplement declares the following:
- Provides specific acquisition regulations that must be followed in the procurement process for goods and services for the Department of Defense and its contactors.
- FAR 252.225-7014 specifies “A Preference for Domestic Specialty Metals” in the manufacturing of fasteners. Berry Act, Buy American.
- The Specialty metals must be melted and manufactured in the United States or a “Qualifying country.”
What is a Qualifying Country?
Qualifying country” means a country with a reciprocal defense procurement memorandum of understanding or international agreement with the United States in which both countries agree to remove barriers to purchases of supplies produced in the other country or services performed by sources of the other country, and the memorandum or agreement complies, where applicable, with the requirements of section 36 of the Arms Export Control Act (22 U.S.C. 2776) and with 10 U.S.C. 2457.
Qualifying countries include the following 27: Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Egypt, Estonia, Finland, France, Germany, Greece, Israel, Italy, Japan, Latvia, Luxembourg, Netherlands, Norway, Poland, Portugal, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom of Great Britain and Northern Ireland.
To keep up to date with DFARs requirements, visit
www.acq.osd.mil/dpap/dars/dfars/html/current/225_0.htm
What is a Specialty Metal?
Title 48 – Federal Acquisition Regulations System, 252.225-7014 Preference for domestic specialty metals.
SPECIALTY METAL DEFINITION
(1) STEEL
(I) WHERE THE MAXIMUM ALLOY CONTENT EXCEEDS ONE OR MORE OF THE FOLLOWING LIMITS: MANGANESE, 1.65 PERCENT; SILICON, 0.60 PERCENT; OR COPPER, 0.60 PERCENT; OR
(II) WHICH CONTAINS MORE THAN 0.25 PERCENT OF ANY OF THE FOLLOWING ELEMENTS: ALUMINUM, CHROMIUM, COBALT, COLUMBIUM, MOLYBDENUM, NICKEL, TITANIUM, TUNGSTEN, OR VANADIUM;
(2) METAL ALLOYS CONSISTING OF NICKEL, IRON-NICKEL, AND COBALT BASE ALLOYS CONTAINING A TOTAL OF OTHER ALLOYING METALS (EXCEPT IRON) IN EXCESS OF TEN PERCENT;
(3) TITANIUM AND TITANIUM ALLOYS; OR
(4) ZIRCONIUM AND ZIRCONIUM BASE ALLOYS.
http://www.gpo.gov/fdsys/pkg/CFR-1996-title48-vol3/xml/CFR-1996-title48-vol3-sec252-225-7014.xml
Specialty Metals Include:
- Stainless steel
- High alloy steel like Grade-BD
- Cobalt Chrome Alloys or Grade 5 Chromium steel with high chromium content
- Nickel Alloys
- Titanium
Aluminum, Carbon Steel & Copper Alloys are not specialty metals and cannot be DFARS.
What is the difference between Domestic & DFARS?
This is a great question! There are 3 main factors used to determine the country where a fastener is made and how they are classified. 1) The origin of the metal 2) the country of melt and 3) the country of manufacture.
DFARs only related to specialty metals, and the country of melt & manufacture. Check with your customer before making any assumptions about what “domestic” means to them. 100% Domestic (metal origin, melt & manufacture) is becoming harder and harder to find. Many products are not available off the shelf and are “made to order” if DFARS or domestic is needed. This will involve a lead time and may have a minimum lot charge.
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!
Brand Equivalent Case Study: Achieving faster delivery & lower costs using functional equivalents
Posted: October 8, 2018 Filed under: keensert, key-locking inserts, Mil-Spec, Supply chain - manufacturing | Tags: keensert, manufacturing, supply chain Leave a commentOctober 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.
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.
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
Buyer’s Guide to One and done Keensert® Ordering
Posted: June 28, 2018 Filed under: DFARS, keensert, key-locking inserts, Mil-Spec, Supply chain - manufacturing, Uncategorized | Tags: keensert, key-locking insert, MS51830, ms51831, MS51832, supply chain Leave a comment
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…..
- 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.
- 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.
- 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.
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.
- 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.
- 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
Posted: April 3, 2018 Filed under: DIN 6325, DIN 7, dowel pin, ISO 2338, ISO 8734, Metric Dowel Pins, Mil-Spec, PRECISION DOWEL PIN Leave a comment7 Things to Know When Buying Metric Dowel Pins
This guide is a follow up to our Dowel Pin Buyer’s Guide. 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:
- 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.
- 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?
- DIN 7
- DIN 6325 & DIN 6325H
- ISO 2338A & ISO 2338B
- ISO 8734
- PRECISION UNHARDENED PRESS FIT DOWEL PINS SS303
- PRECISION HARDENED DOWEL PINS SS416
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 |
DIN7ISO 2338ISO 2338A |
Rounded or beveled |
Steel (least common)300 Series Stainless Steel includingA1=18-8, 303, 304A4=316 |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M.8-M20 |
ISO 2338B |
Rounded or beveled |
300 Series Stainless SteelA1=18-8, 303, 304 |
H8 diameter tolerance |
Unhardened |
M1.5-10 |
DIN 6325DIN 6325HISO 8734AISO 8734 |
Rounded on one endBeveled on one end |
Alloy Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 52-62 |
M1-M25 |
Precision Unhardened |
Rounded |
300 Series Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Unhardened |
M1-M12 |
Precision Hardened |
Rounded on one endBeveled on one end |
416 Stainless Steel |
M6 diameter toleranceSlightly Oversizedaka Press Fit |
Hardened toRHC 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.
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