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 of 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.

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.

What is a Spring Pin?

By Donn Saylor
Updated: May 17, 2024

A spring pin is a type of hardware fastener that mechanically links two items together. The spring pin goes by a variety of names, including spring tension pin, slotted spring pin, sellock pin, and roll pin. Known for their durability and strength, spring pins rarely budge out of place and can bear up under immense pressure.

The traditional spring pin is made out of steel and is tube-shaped with a split down the middle. The diameter of the pin is a bit larger than the hole into which it fits. Once it is fastened into the hole, the spring pin pushes against the perimeter of the hole, creating pressure, or a spring-like force. This action results in a strong surge of friction that locks the pin in place tightly and securely.

Steel spring pins may also come equipped with actual springs. Known as a spring-loaded pin, this type of fastener is often used for technological purposes, such as cable termination, internal battery connection, and as part of a charging base for portable devices. The spring that is fitted into each spring loaded pin works to solidly hold parts in place and ensure a steady electrical flow.

A spring pin does possess one major drawback, however. Their small size and unique design make them difficult to handle, and since they often need to be screwed in by hand, this makes them a challenge to work with and hold steady. A spring pin tool comes in handy for inserting spring pins with relative ease. Small and slender, these tools fit perfectly into the head of spring pins and make for simple installation; they also reduce wear and tear on the pin itself and most can be used to access hard-to-reach places. Spring pin tools typically contain a magnetic guide that holds the spring pins in place, guaranteeing pins are not lost, and the whole work process moves more smoothly.

Spring pins are sometimes confused with other types of fasteners that function in similar ways. Lynch pins, R-clips, and split pins all operate in a manner comparable to spring pins. They are slightly larger than the hole in which they are to be placed, and when they are inserted, they create friction and a dependable hold. These other types of clips, however, are no match for the strength of spring pins, which can hold up under rotational pressure, side loads, and other deterrents.

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.
Discussion Comments
By anon232235 — On Nov 29, 2011

Great article. You mentioned it expands to fill a hole, but failed to mention the most important bit! That it connects two independent objects via a spring-pin inserted in a cylindrical cutout on both objects.

By anon232234 — On Nov 29, 2011

This does not explain what it does. A two second internet search will tell you what a spring pin is. The only reason anyone would come here is to learn what it's for. Please provide some more information.

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.