A tension pin is a slotted cylindrical fastener, heat-treated to achieve optimal toughness, resilience and shear strength. In manufacture, it is formed to a controlled diameter greater than the hole into which it is pressed. The self-locking tension pin is stronger and costs considerably less than mild carbon steel straight pin, taper pins or grooved pins of equivalent sizes.

Being hollow, the tension pin is lighter than a solid pin. Because it is self-locking, it saves the weight of projecting heads, tabs and extra locking parts.