Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number Z620-021-000B found under Screw Cap Socket He by Alkan. The National Stock Number assigned to this part is 5305145522455, 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 Z620-021-000B.