Metric spring pins (also called metric roll pins, tension pins, and expansion pins) are hollow and slotted across the length to facilitate tension. Metric spring pins are made of carbon spring steel, a pliable yet effective steel ideal for this pin's applications.

Metric spring pins can be used for many jobs, including electrical connectors in circuits, terminals, actuators, wire harness fixtures, studs, hinges, fixing pulleys or gears to shafts, and more. They permit a wider tolerance than drive pins, taper pins, or collar pins because of their greater flexibility. In addition, the tapered ends of metric spring pins make them relatively easy to insert and drill.