Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SHF121 17SA18A found under Stud Plain by Fairchild Corp. The National Stock Number assigned to this part is 5307013905073, and the Federal Supply Class is 5307 Studs. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like SHF121 17SA18A.