Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PB4-40SM10 found under Thumbscrew by Alcoa Global Fasteners Inc. The National Stock Number assigned to this part is 5305008478119, 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 PB4-40SM10.