Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B552-3100-20 found under Retainer Turnlock Fastener Eject by Electric Boat Corporation. The National Stock Number assigned to this part is 5325014989232, and the Federal Supply Class is 5325 Fastening Devices. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B552-3100-20.