Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SS-502 found under Washer Flat by Phoenix Specialty Mfg Co Inc. The National Stock Number assigned to this part is 5310013412179, and the Federal Supply Class is 5310 Nuts And Washers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like SS-502.