Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SFR 4 40X1 2 B 0 found under Screw Machine by A P M Hexseal Corporation. The National Stock Number assigned to this part is 5305004201756, 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 SFR 4 40X1 2 B 0.