A-P12X100-AI Roll Pin, 12 MM x 100 MM, 2 packTwo New Aftermarket Replacement Roll Pins, 12 MM x 100 MM 2 Pack This listing includes two (2) metric slotted spring roll pins, each measuring 12 MM in diameter and 100 MM in length. Roll pins also known as spring pins, tension pins, or slotted pins are hollow, slotted fasteners made from carbon spring steel that compress slightly on installation and expand against the bore wall to hold securely in place without threading or heading. They are a