Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2B9-4170 found under Setscrew by Lake Shore Systems Inc. The National Stock Number assigned to this part is 5305013748305, 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 2B9-4170.