Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number R66172B43469 found under Washer Flat by Unifab Industries Inc. The National Stock Number assigned to this part is 5310008212366, and the Federal Supply Class is 5310 Nuts And Washers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like R66172B43469.