Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 5501-12-4 found under Elbow Pipe by Air Way Manufacturing Company. The National Stock Number assigned to this part is 4730012220908, and the Federal Supply Class is 4730 Hose Pipe Tube Lubrication And Railing Fittings. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 5501-12-4.