Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A157D found under Nut Selflocking Pla by Martin Baker Aircraft Co Ltd. The National Stock Number assigned to this part is 5310009942000, 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 A157D.