Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SM-C-657639 found under Holder Solenoid by Fortners Machine Shop Inc. The National Stock Number assigned to this part is 5945011890474, and the Federal Supply Class is 5945 Relays And Solenoids. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like SM-C-657639.