pin slotSlotted 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.Ball lock pins and slot pins are machine parts that make it easy to connect parts, simply by inserting the specially desned pin part. Convenient because no