Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number CA21150-4-2HS found under Screw Cap Socket Head by Alcoa Global Fasteners Inc. The National Stock Number assigned to this part is 5305011377042, 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 CA21150-4-2HS.