Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number NAS538C7-040 found under Bushing Sleeve by National Aerospace Standards. The National Stock Number assigned to this part is 3120016709864, and the Federal Supply Class is 3120 Bearings Plain Unmounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like NAS538C7-040.