Particular in design for their shape and application, spring pins are unthreaded fasteners that must be inserted into a hole with a diameter that is smaller than the pin itself. Also commonly referred to as roll pins, these components are built with an open seam down their length, allowing for a snug fit once placed. Manufactured with a chamfer on each end to facilitate easy insertion into a hole, spring pins are typically made from thin sheet metal meant to decrease in diameter and curve to form the outer expansion of the pin. Available in two primary pin types, slotted pins and spiral pins, these mechanical fasteners are the perfect solution for mating parts together or fastening one shaft to another. To better understand how spring pins work, we will discuss their common types and how you can best apply each to satisfy your part needs.