Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PT521 found under Pin Straight Headed by Jpi Transportation Products Inc. The National Stock Number assigned to this part is 5315003546851, and the Federal Supply Class is 5315 Nails Machine Keys And Pins. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like PT521.