Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1604893 found under Valve Balanced Thre by Koehring Co. The National Stock Number assigned to this part is 4820004888346, 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 1604893.