Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4020-R-SS-500-12 found under Spacer Sleeve by Accurate Screw Machine Co. The National Stock Number assigned to this part is 5365013224729, and the Federal Supply Class is 5365 Bushings Rings Shims And Spacers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4020-R-SS-500-12.