Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number BK-7681-VB found under Cock Shutoff Screw by Nash Engineering Company Inc The. The National Stock Number assigned to this part is 4820014361089, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like BK-7681-VB.