Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number CB57-42203 ITEM 21 found under Key Woodruff by Aai Corporation. The National Stock Number assigned to this part is 5315011868503, and the Federal Supply Class is 5315 Nails Machine Keys And Pins. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like CB57-42203 ITEM 21.