Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 645 10028B found under Washer Recessed by Apw Electronics Ltd. The National Stock Number assigned to this part is 5310991228234, 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 645 10028B.