Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4821-52000 found under Chain Roller by Rapistan Corp. The National Stock Number assigned to this part is 3020005279774, and the Federal Supply Class is 3020 Gear Pulley Sprocket And Transmission Chain. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4821-52000.