copper tube bending pipe bending machine tube end forming COPPER TUBE BENDING The Swing-away Wiper die assembly is used for copper tube bending applications requiring a mandrel and a wiper die. The swing-away wiper die accessory is particularly advantageous when bending part shapes having short ends where trim material is added to avoid interference between the carriage and the wiper die. By reducing machine and tooling interference, the swing-away wiper die minimizes trim (scrap length) on the trailing end of the tube.