Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PK20 4D found under Union Pipe by Precision Aircraft Machining. The National Stock Number assigned to this part is 4730014237545, 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 PK20 4D.