Cotter Pin!? What the heck is that?

Welcome back to the next installment 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. This week, we are introducing you to our friend, the Cotter Pin!

Cotter Pins, AKA Split Pins, R Clips or R Pins, Hitch Pins or Hitch Clips, Safety Pins, Circle Cotters, Retaining Pins or Locking Pins, may not be the most renowned piece of hardware, yet they have been quietly holding together our world in more ways than you might imagine. For starters, these pins are non-threaded fasteners, which means that they do not have the risk of loosening due to vibrations as is the case in some screw or bolt connections. Furthermore, Cotter Pins are easy to install/remove and are inexpensive to produce—making them valuable & cost-effective components that guarantee the stability and functioning efficiency of numerous mechanisms across a variety of industries. Keep reading to learn more about these pins and to see if they would be a great fit for your next big project.

What are Cotter Pins?

Cotter Pins are double-structured pins crafted from semi-round wires, that have a loop on one end that serves as a head. The completed component showcases one wire end extending past the other, ending with a chisel-like point.

At the most basic, cotter pins are fasteners that are used to secure various assemblies in place. Typically, they are shaped like a “T” or an “R”, and are inserted into holes that run through the parts to be connected. They are then split into two prongs at the opposite ends, which are then bent to prevent the pins from slipping out and to securely hold the assemblies together.

One key advantage of cotter pins is their inherent simplicity. With their straightforward design, they can be easily installed and detached without the necessity for any specific tools. Furthermore, they offer robust links that prevent the secured pieces from becoming loose or disassembled. When used with castle or slotted nuts, they become a safety locking device.

Another important benefit offered by cotter pins is their ease of removal, which enables swift disassembly or maintenance tasks. When the need arises to dismantle/disassemble components, cotter pins can be easily taken out by straightening or bending back their split ends to their original position. This feature simplifies repair or maintenance operations.

Cotter pins also allow for a certain degree of motion (pivot) depending on how they are installed. This is beneficial in applications like bicycle crank arms where you want the crank to remain secure while also allowing it to rotate.

Who uses Cotter Pins?

Cotter Pins are widely used across a range of industries due to their simplicity, reliability, and versatility. The following are some primary industries where cotter pins are frequently employed:

  • Aerospace Industry: Cotter Pins play a vital role in the aerospace industry, where safety and reliability are paramount. They are used to secure critical components such as landing gear, engine parts, and control linkages, ensuring that they remain in position during flight. For example, control linkages encompass control surfaces such as ailerons, elevators, and rudder, as well as the cockpit controls, all of which have numerous pivot points requiring both security and mobility. Cotter Pins are perfectly suited for these uses.
  • Automotive Industry: In the automotive industry, cotter pins are utilized in various components, particularly in suspension systems, steering linkages, transmission linkages, wheel assembly, brake system, etc. They secure ball joints, tie rod ends, and other critical parts to ensure safe and reliable vehicle operation.
  • Agriculture Industry: In the agricultural sector, cotter pins serve the purpose of fastening elements in various farming machinery, including plows, harrows, and cultivators. Cotter pins also find use in several components of tractors, including anchoring the joint connections in the steering mechanism, maintaining components in the transmission system, and fastening parts in the hydraulic systems.
  • Marine Industry: Within the marine industry, Cotter Pins are widely employed to secure clevis pins, turnbuckles, and various fittings in rigging systems and boat hardware. For instance, within marine engines, cotter pins are often used to secure various components and assemblies, such as linkages, connections, and valves. Offering a swift and secure fastening solution, these pins demonstrate reliability even in corrosive marine environments.
  • Military and Defense: In the military and defense industries, cotter pins are used to fasten components in weapons, vehicles, aircrafts, naval assets, and communication equipment. In addition, Cotter Pins are deployed in a wide array of other portable gear and systems utilized by military personnel in operational settings. These can encompass everything from temporary bridges and fortification structures.

Other industries that make use of Cotter Pins are: the Industrial and Machinery Industry, where Cotter Pins are used for securing components, such as pulleys, gears, and levers; the Mechanical and Electrical Engineering Industry, where they are used to to fasten parts, such as bolts, nuts, and shafts; the Recreational and Sports Equipment Industry, where they secure various moving parts and components found in recreational equipment, such as bicycles, motorcycles, and sports gear; the Construction and Heavy Equipment Industry, where these pins are used for various applications, including securing hitch pins, linkages, and hydraulic connections; and the Furniture and Manufacturing Industry, where these pins are utilized to secure joints, hinges, and other components in conveyor systems, furniture assembly, and .

What standards, materials and sizes are available?

Materials: Cotter pins can be manufactured from different materials like steel, stainless steel, brass, and aluminum. Steel cotter pins are often enhanced with a zinc coating for added resistance to corrosion. Stainless steel pins are favored for their superior strength and corrosion resistance, particularly in harsh environments.

Sizes: Cotter pins come in a spectrum of sizes, generally ranging from 1/32″ to 3/4″ in diameter and 1/2″ to 6″ in length. The appropriate size is dictated by the application and the dimensions of the hole where the pin will be placed.

Standards: Various nations and regions adopt their own standards for cotter pins. Some of the most frequently used ones include the American Society of Mechanical Engineers (ASME), American National Standards Institute (ANSI), British Standards (BS), Military Specification (Mil-Spec) Standard, and the Deutsches Institut für Normung (DIN).

Commercial Standards include: ASME B18.8.1

Mil-Spec standards include: MS9245

Are there other factors to consider?

YES!! The efficacy of cotter pins are greatly influenced by their proper installation and maintenance. The following list has crucial points to keep in mind.

  • Selection: Opt for cotter pins that fit into the hole securely without being overly tight. The length should be sufficient for the prongs to be bent appropriately without leaving excessive overhang.
  • Installation: During installation, ensure the prongs are split and bent sufficiently to secure the pins. Tools like pliers or a cotter pin puller can aid in the process of installation and removal.
  • Inspection: Regular checks on cotter pins are crucial, particularly in applications under high-stress or where safety is paramount. Look out for signs of wear, corrosion, or distortion, indicating potential need for replacement.
  • Replacement: When extracting cotter pins, it’s typically advised to substitute them with new ones, as the bending and straightening process can fatigue the metal, undermining their strength.

Cotter Pins at MF Supply

We currently offer:

  • A full range of commercial parts, including parts that are ROHS compliant.
  • Inch Cotter Pins are now available for online purchase at our website! Stock sizes include 1/16 through 1/2 in Steel with a Chisel Point and Zinc Plating, as per standard ASME B18.8.1 specifications.
  • Mil-spec Cotter Pins MS9245 are also available for online purchase. Stock sizes include 1/32 through 5/32 in T321 Stainless Steel , with Manufacturers Certifications.
  • Please send a Request for Quote for any other Cotter Pin not listed on our website.
  • Brand names and generic equivalents.
  • Custom made parts per print.

For more detailed information on Cotter Pins or other products, 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.


MF Supply Work With Us

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. 


Over 216 Unique Retaining Rings Now Available for Online Purchase!

MF Supply is a trusted supplier of Retaining Rings to OEMs, Manufacturers and Industry. We now offer a wide selection of over 216 Retaining Rings in stock & available for purchase on our website alone. You’ll find in stock Inch & Metric E-Style (E/SE), External and Internal Retaining Rings in a variety of sizes and materials—such as Steel and Stainless Steel. We offer Brand Names and/or Equivalents to National Catalog and OEM brands including: Anderton, Ellison, IRR, Rotor Clip® and Waldes Truarc®.

Common Uses of Retaining Rings at MF Supply

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.

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.

In-Stock Standoffs and Spacers at MF Supply

At http://www.mfsupply.com, we currently offer over 216 Retaining Rings in E-Style (E/SE), External (used on shafts) and Internal (used for bores) Styles. They also come in many sizes (including Metric sizes), and the general range is from 1/16 to 10″. Materials include Carbon Spring Steel and PH15-7 Stainless Steel. Check out our handy cross reference sheets here.

Below is a list of the Retaining Rings currently available for online purchase at our website.

E-Style Retaining Rings (E/SE)

External Retaining Rings

Internal Retaining Rings

Make ordering the Retaining Rings you require a breeze by visiting our website today, or reach out to us to request a quote for standard or special custom made parts per print.

What the heck are Retaining Rings anyway?

Would you like to learn more about Retaining Rings? Don’t sweat it! Read our recent blog post “Retaining Rings!? What the heck are those?“, from our “What the Heck is that” series to learn more about this category of fasteners.

Can’t find what you’re looking for?

If the OEM brand, size or material you need is not listed above or on our website Request a Quote today, and our MF Supply team of sourcing experts can help 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.


MF Supply Work With Us

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. 


Retaining Rings!? What the heck are those?

Welcome back to 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 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, e-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 lighter, cleaner, 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 (radially assembled). 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, Arcon, Rotor Clip, Waldes/Truarc. We can supply the brand name or generic alternatives.
  • 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 currently offer:

For more detailed information on Retaining Rings, 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.


MF Supply Work With Us

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. 


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!