Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M10X40 SST304 found under Screw Cap Socket He by Johnson Rubber Co The. The National Stock Number assigned to this part is 5305013685983, 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 M10X40 SST304.