spring pin In many machines and structures, a spring pin is a fastener that relies on its own elasticity to fasten and locate parts.It is typically a slotted, cylindrical pin that expands against the hole after insertion, creating a tight fit that prevents loosening. This property lets spring pins both withstand shear and absorb vibration, making them an indispensable “invisible guardian” in many systems. --- How to Determine the Right Spec？ When selecting a spring pin, the