Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number ST3M653C6-21A found under Screw Shoulder by Valley Todeco Inc. The National Stock Number assigned to this part is 5305015681024, 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 ST3M653C6-21A.