Spring-Tension Pins

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Spring tension pins, also known as roll pins or slotted spring pins, are unthreaded fasteners that lock two components together. They are hollow fasteners made from spring steel that have a slot, and are designed for use in double shear applications. The pin's spring action allows it to compress as it assumes the diameter of the hole, and the radial force exerted by the pin against the hole wall retains it in the hole.

Spring pins have a body diameter that is larger than the hole diameter, and a chamfer on either one or both ends to facilitate starting the pin into the hole. They provide a flexible and secure connection between components, absorbing vibration and shock. They are used to prevent lateral movement while allowing slight flexibility.

Spring pins may be used to retain a shaft as a journal in a plain bearing, as a type of key to fasten one shaft to another, or to precisely fasten flat faces of mating parts together through symmetric hole locations. Spring pins are available in a variety of materials, including alloy steel, aluminium, carbon steel, copper, galvanized steel, plastic, stainless steel, and zinc.