Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 542 20 21-87 found under Bolt U by Target Inc. The National Stock Number assigned to this part is 5306016301712, and the Federal Supply Class is 5306 Bolts. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 542 20 21-87.