Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number BS78505BLACK found under Clinch Plate Turnbutton Fastener by Trw Inc. The National Stock Number assigned to this part is 5325003718108, and the Federal Supply Class is 5325 Fastening Devices. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like BS78505BLACK.