Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 303 2 56X1 16 found under Setscrew by Allen Mfg Co. The National Stock Number assigned to this part is 5305010446555, 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 303 2 56X1 16.