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What is a Spring Pin?

Donn Saylor
Donn Saylor

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.

Man with a drill
Man with a drill

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.

Discussion Comments


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.


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.

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