Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AZ12.5 found under Washer Lock by Tuthill Corporation. The National Stock Number assigned to this part is 5310011438231, 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 AZ12.5.