Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A53XX found under Pipe Metallic by Bethlehem Steel Corp. The National Stock Number assigned to this part is 4710002648563, 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 A53XX.