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!

Request A Quote

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

Precision Shoulder Screws Buyer’s Guide

5 Things to Know When Buying Precision 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 far 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. The exacting tolerance of Precision Shoulder Screws makes 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.

Our goal is to make the buying process easier. This guide offers creative solutions to help you save money and reduce long lead times by educating you on your options, including how to use brand alternatives.

  1. What is a Precision Shoulder Screw? 

Precision Shoulder Screws are generally classified as part of the electronic hardware family. They resemble socket cap screws with an enlarged, unthreaded cylindrical shoulder under the head, and are used to hold parts together within a precision assembly.  Sometimes referred to as “tight tolerance” shoulder screws, they are not governed by any official ANSI or ASME standard.

Precision shoulder screws are composed of three main parts: the head, the shoulder and the thread.

  1. What materials and sizes are available?

Precision Shoulder Screws are readily available off the shelf in type 18-8/303 stainless steel and 416 stainless steel.

Standard stock sizes for the shoulder diameter are Inch from 1/8 to 1/2 and Metric from M4 to M12. 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!

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 shoulder diameter, shoulder length, thread size, material and drive type; for example: 3/16” shoulder diameter x 1” long x 8-32 thread in SS18-8 with a hex-socket drive.

Precision shoulder screws are available in hex socket and slotted drives. Philips, torx and star drives may be available in certain sizes as well.

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. Are there other factors to consider?

YES! 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.

Popular brands include: Amatom, Cambion, Concord, Globe, HH Smith, Keystone, Lyn-tron, Misumi, Pic Design, RAF, and WM Berg. A comprehensive selection of Precision Shoulder Screws is also offered by McMaster-Carr (tight tolerance series), MSC, and Grainger.

Let’s take the above example of a 3/16” shoulder diameter x 1” long x 8-32 thread in SS18-8 (300 Series) with a hex-socket drive.  This part is offered by the seven brands (yes, seven!) listed below under the following part numbers:

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

You can also find Precision Shoulder Screws under their Mil-Spec numbers, which include MS51575 and MS51576 and are DFARS compliant with full paperwork. The above part is equivalent to a Mil-Spec MS51576-14.

  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.

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 about Precision Shoulder 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.

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


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!

 


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.


Buyer’s Guide for Using Functional Equivalents to OEM Brands

5 Things to Know when Comparing Fastener Brands to Generic Alternatives

This year, we’ve discussed how the trademarked brand Keensert® is often available as a Mil-Spec or generic branded key-locking insert. We also reviewed how national brands of precision shoulder screws, such as Amatom, Concord, RAF and others are also offered by McMaster-Carr (tight tolerance series), MSC, Grainger and generically.

But how exactly do you determine which categories of fasteners cross to generic alternatives? This guide offers creative solutions including when to cross, and how to save money and reduce long lead times by using brand alternatives.

1.  What is a functional equivalent when it comes to fasteners and precision components?  

You can find hundreds of registered trademark-branded fasteners and components in the industrial marketplace. 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.

2.  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 functional equivalent.

Use this handy 4 point checklist as your guide:

  • Does your bill of materials specifically call for the OEM brand-name fastener or component?
  • Can you live with the lead time or will having parts sooner improve delivery of the final product?
  • Will your supplier provide a certificate of conformance?
  • Will saving money help you be more competitive?

3.  What categories of fasteners are available as generic or functional equivalents?

Popular categories include adhesives and sealants, anchors, bits and nutsetters, cage nuts, flex type lock nuts, handles, Keenserts, knurled thumb screws, nylon insert stop nuts,  precision shoulder screws, retaining rings, rivets & blind threaded inserts, self-clinching, fasteners, spacers and standoffs, speed clips, spring nuts, weld nuts, weld studs, and woodworking screws.

4.  What brands of fasteners should I consider crossing to their generic or functional equivalent?

A sample list of brands that have generic alternatives: 

3 STAR RIVETS USA, ABBATRON®, ALCOA, AMATOM®, APEX®, ARCONIC®, ATLAS®, AVDEL®, AVK®, B. F. GOODRICH, BOLLHOFF, BUCKEYE, CAPTIVE, CELUS®, CHERRY®, CONCORD, FASTENAL, GESIPA®, GRIPCO®, GLOBE ELECTRONICS, H. H. SMITH, HUCK, INDUX, INTERFAST, KEYSTONE, LOCTITE®, LYN-TRON, MACLEAN­ESNA®, MARSON®, MCMASTER-CARR, MISUMI, MSC INDUSTRIAL, PEM®, PIC DESIGN®, POP®, POWERS®, QUICKSCREWS, RAF, RED HEAD®, ROTOR CLIP®, SHEREX, SIMPSON, SOUTHCO®, SPS TECHNOLOGIES, TINNERMAN®, U. S. ANCHOR. VIP, W. M. BERG, W. W. GRAINGER, WALDES TRUARC®.

5.  What are the advantages of using functional equivalents?

Brand names are great, and when they are in stock, available and required by your customer, then you can buy them with confidence in their quality. However, 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.

Brands and Functional Equivalents at MF Supply

Supplying a full range of fastener products and services, MF Supply is an authorized distributor of Amatom/Carey, Captive (Pem equivalent), Chrislynn Inserts, Concord, EZ-Lok, Lok-mor, Lyn-tron, Microplastics, Shear-loc, S&M Retaining Rings, and Unicorp, as well as a distribution partner for many others. We have an expertise in dowel pins, inserts and Keenserts and domestic and Mil-Spec products.

We provide functional equivalents to expensive brand name fasteners and help our customers save money while reducing long lead times. Check out our recent case study where a functional equivalent was substituted for an OEM brand, reducing costs by 37% and shaving lead time. This time and money savings gave the manufacturer an advantage over their competition, which helped them win the job.

For more detailed information about brands we commonly cross, 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!

MF Supply is a WBE/WOSB certified stocking distributor of precision fasteners and electronic components, specializing in precision hardware including precision shoulder screws. For more than 40 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services.


What the heck is that fastener? The year in review – 2014.

Newsletter

Volume 12  

December 17, 2014

What the heck is that fastener?

Welcome to 2014’s final edition of our “What the heck is that” newsletter and blog where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products.

December is a great time to reflect on all we have learned so far this year and get educated on topics that impact manufacturers. So keep reading for a chock-full of fastening info!

Take a read down memory lane as we review our previous blogs and reacquaint you with some of our most popular topics.  Visit our blog directly at http://blog.mfsupply.com/  for full articles and information.

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, lock the fastener in place within a rack hole.

Cage Nuts are commonly used to mount lighting systems, electrical equipment or instruments onto rail racks.

Mil-spec DFARS

Mil-spec is the informal name for the military standard the U.S. Department of Defense uses in the production of military equipment and supplies.   The government maintains a list of qualified factories [QSLM] and suppliers [QSLD] that pass the highest quality control standards for screw attributes, including: dimensions, tensile strength, hardness, threads and drive type, just to name a few.

DFARS pertains to fasteners made from “specialty metals” including: stainless steel, high alloy steel like Grade-BD, or Grade 5 Chromium steel . For a fastener to be DFAR Compliant, the metal used to make the fastener must be melted and manufactured in the United States or a qualifying country. To keep up to date with DFARs requirements, visit http://www.acq.osd.mil/dpap/dars/about.html section 252.225.

Wire Insert

Wire inserts are precision-formed continuous helical wire coils that provide permanent, wear-resistant threads which exceed the strength of the parent material.

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.

Sometimes referred to by the brand name “Heli-coil”, wire inserts can be locking or nonlocking, tanged or tangless.

Standoffs and Spacers

Often classified as Electronic Hardware, or Panel Hardware, Standoffs are hex or round shaped fasteners which have a body and two threaded ends. Spacers are similar to Standoffs, however, Spacers are unthreaded with an inside clearance hole.

Both are commonly used to mechanically support, connect and position components within assemblies.

Standoffs and spacers are often ordered by their brand name, including: RAF, Amatom, Concord. Globe, HH Smith and Keystone.

Precision Shoulder Screws

Precision Shoulder Screws are tight tolerance screws which are comprised of 3 main parts: the head, the shoulder and the thread.

Used to locate or hold parts together within a precision assembly or a fixture, when installed, the unthreaded shoulder acts as a shaft for rotating items such as bearings and bushings, precision spacing, machinery support, and motion guiding.

Common brands are PIC and WM Berg, RAF, Mcmaster-Carr and MSC.\

Dowel Pins

Dowel Pins are solid, headless cylindrical shaped straight metal pins with a centerless ground finish.

Often used as a hinge, shaft or pivot to locate or hold parts together within a precision assembly or a fixture, Dowel pins can be Standard, Oversized or Undersized.

Common brands are Holo-krome and PIC and WM Berg.

Retaining Rings

Shaped like an open ring and made of metal, Retaining Rings can be coiled from wire, stamped or laser cut.

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.

Common brands are Rotor-Clip and Waldes,Truarc.

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.

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.

 Set screws

Set screws are externally threaded fasteners with a drive (commonly hex socket) on one end and one of 7 (yes 7!) point styles on the other.

Designed to fasten one object inside another, set screws are commonly used within assemblies with rotating items such as pulleys or wheels where a component is locked onto a shaft.

And that’s all she wrote……

You might have noticed an important theme here.  Many fasteners are used as part of an assembly that involves a shaft with moving parts.  And in the fastener world, we’ve got options.  Lots and lots of options.

If there are fasteners that you would like us to profile, please be in touch.  And if you need help finding the right screw for you and your application, you know where to find us.  See you in 2015!

Warm Regards,

Robin

The Screw Lady


What the heck are Set Screws?

Newsletter

Volume 11   

October 30, 2014

What the Heck are Set Screws?

set screw

We begin the fourth quarter of 2014 with an introduction to the Set Screw. A Set Screw is a headless screw (appropriate for our Halloween edition) fully threaded from end to end.  Traditionally classified within the Socket family of products, Set Screws are comprised of 3 main parts: the drive, the thread and the point.  They (generally) have a hexagonal drive on one end, and a point on the other.  They are often used in conjunction with a shaft collar, and like their functional relatives, the Dowel Pin, Retaining Ring and Shoulder Screw, they are used as part of an assembly (you should be getting used to reading about assemblies by now :)).

Who uses Set Screws?

Set screws are used in many industrial and mechanical devices, particularly within 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?

The set screw works by exerting compressional force through the tip to prevent the relative movement between the two objects so each part can function as intended.  This is different than traditional screws that hold objects together with threads.  Who would have thunk that a headless screw could have so much power!

Check out this video for a demonstration of installation and application: https://www.youtube.com/watch?v=U7hragiTmZI

What options are available?

Like most fastening products, the bevy of options is plentiful (and sometimes exhausting if you ask me!).  Once the basics like the diameter, thread, length and material are determined, the main decisions that need to be made are the drive and point style.

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.  There are 7 (yes 7!)  main points that are available, and each serves a slightly different purpose.

  1. 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)
  2. Knurled Cup -a variation of the Cup point, this style has knurls for a stronger grip.
  3.  Cone– a very sharp point wedges into the inner object to hold it in place permanently. 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)
  4.  Flat-designed for flexibility when frequently resetting or relocating objects on hard steel shafts where minimal damage to shaft is necessary. Affordable and easy to install, Flat point set screws can be moved without damaging the inner object. (DIN 913)
  5.  Oval-its 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 inner object.   The Oval point set screw is the most practical type for situations where the inner and outer objects require regular adjustments.
  6. 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)
  7.  Nylon tip – resembling a Half dog point, the soft nylon tip is used to grip curved or textured surfaces.

Are there other factors to consider?

From what you’ve just read, it appears that the choices are abundant, yet, in practice, many of the combinations that engineers are seeking are only available as specials and have to be custom made.  For example, if you are looking for a fine thread cone point set screw in stainless steel, you may be told it has to be custom made with a minimum run and a long lead time.  Make sure to check with our sourcing experts first before you change your requirements!

So, you might be wondering how to get what you need and get it fast?  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. The most common material is hardened alloy steel with a thermal black oxide finish, as per ASME B18.3.   Socket set screws come standard with 3A thread fit and a Rockwell hardness of C45-53.

Commercial, Mil-Spec or Brand name?

Finally, Set Screws can also show up under their most popular domestic brand name (Holo-krome) or their Mil-spec numbers, which are DFARS compliant with full paperwork. 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.

Set Screws Available at MF Supply:

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.

For more detailed information on Set Screws, visit us at http://www.mfsupply.com/category_s/1914.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 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!