We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Cotter Pin?

Malcolm Tatum
By
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Cotter pins are simple devices that are used in many different types of machinery. The exact configuration and use of the pin will vary from one location to another. For the most part, the pin is utilized to provide a secure connection between two components that is not loosened while the machinery is on operation. Just about any type of machinery that employs the use of nuts and bolts in the design is also likely to require the presence of a cotter pin.

In the United States, the cotter pin is typically a slender pin that is split in the middle. Stainless steel is often the metal of choice for these devices. The head of the pin is normally larger in diameter than the body of the pin, making it easy to slide the device into place through a nut or bolt. Once in place, the two tines that make up the body of the pin can be bent around the nut or bolt to help secure the components in position securely. In this application, the cotter pin performs a function similar to a rivet, but can be used when a rivet is not a practical solution.

The cotter pin in manufactured in a variety of sizes. This makes it possible to utilize this type of fastening device in both small and large applications, ranging from simple tools and appliances used at home to large pieces of machinery that are used in textile plants, electronic assembly plants, and other large scale operations. Relatively inexpensive, cotter pins are often purchased in lots of a hundred or more, depending on the size and type of material used to create the pins.

There are a number of different types of cotter pins in use today. Among the cotter pin assortment utilized in different settings is the R-clip pin and the bowtie pin. There is even a round or circular cotter pin that is known as the circle cotter. Each of these perform the same basic function of securely connecting two components, but are utilized in different settings, based on the type of machinery involved and the size of the components that need to be connected.

In the United Kingdom, a cotter pin may also have a slightly larger body that allows the device to be firmly wedged through holes in two components to hold them in position. This is slightly different from the thinner body found with most cotter style pins in the United States, but is especially helpful where there is no real desire to allow any type of friction or slippage between the connected components. As more corporations have become international in scope, the variety of pins that are part of the cotter pin family has sometimes led to confusions, based on different understandings of what constitutes this type of pin in different cultures and settings.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Malcolm Tatum
By Malcolm Tatum , Writer
Malcolm Tatum, a former teleconferencing industry professional, followed his passion for trivia, research, and writing to become a full-time freelance writer. He has contributed articles to a variety of print and online publications, including About Mechanics, and his work has also been featured in poetry collections, devotional anthologies, and newspapers. When not writing, Malcolm enjoys collecting vinyl records, following minor league baseball, and cycling.

Discussion Comments

Malcolm Tatum

Malcolm Tatum

Writer

Malcolm Tatum, a former teleconferencing industry professional, followed his passion for trivia, research, and writing...
Learn more
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.