Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 646789 found under Tube Assembly Metal by E A Patten Co The. The National Stock Number assigned to this part is 4710000837037, and the Federal Supply Class is 4710 Pipe Tube And Rigid Tubing. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 646789.