Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number GS520CM4 found under Fastener by Alcoa Global Fasteners Inc. The National Stock Number assigned to this part is 5325011121488, and the Federal Supply Class is 5325 Fastening Devices. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like GS520CM4.