Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number P21-1054-1 found under Thumbscrew by Hardigg Industries Inc. The National Stock Number assigned to this part is 5305013304447, and the Federal Supply Class is 5305 Screws. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like P21-1054-1.