a small cylindrically shaped pin used to close shackles or outhaul fittings, or to fasten a turnbuckle to a chain plate.
A pin used to close the opening of a shackle or clevis.
A clevis pin is a type of fastener that will allow rotation of the connected parts about the axis of the pin. A clevis pin consists of a head, shank and hole. The hole passes through the shank at the opposite end of the pin from the head.