Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4X1+40DX1+32SST found under Washer Flat by Allmetal Screw Products Corp. The National Stock Number assigned to this part is 5310002713215, 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 4X1+40DX1+32SST.