Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 16990-3F-20C found under Screw Cap Socket He by Sps Technologies Inc. The National Stock Number assigned to this part is 5305014091713, 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 16990-3F-20C.