pin slotUsing the pin and slot, you can put a really tht tolerance on the pin and it then put it in a press fit on one side, and a tht slip fit on the other. This will position it well, and the slot will make sureSlotted Spring Pin. ... . COT Cotter Pins (JIS B 1351) MB Curved Washers. SSP Snap-Pins (R Pin) (JIS B 1351) RCP-Type External Spring Pins. JIS B 1251.