Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 377-SS-20 found under Setscrew by R A F Electronic Hardware Inc. The National Stock Number assigned to this part is 5305013984039, and the Federal Supply Class is 5305 Screws. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 377-SS-20.