Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 18-420 found under Impeller Fan Axial by Almco Inc. The National Stock Number assigned to this part is 4140009804969, and the Federal Supply Class is 4140 Fans Air Circulators And Blower Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 18-420.