Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number D40-0003 ITEM 20 found under Washer Spring Tensi by Dante Valve Company Inc. The National Stock Number assigned to this part is 5310016285061, 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 D40-0003 ITEM 20.