pin slotAlso known as Sel-loc pins, roll pins, tension pins, slot pins and s-lok pins. They are an un-headed fastener used to secure 2 or more parts. Spring pins are made from hh tensile steel and are very popular because it exerts constant tensionFure 2. The pin on the left determines the X position of the workpiece. To overcome these issues, one of the pins can be assembled into a slot. Thus, the pin in the hole removes