The dies should be a good fit onto the machined register on the bend head, and must always be securely fastened down. Dies are manufactured from various grades of steel dependant upon the type of application. AddisonMckee Tube Bending Guide FAULT FINDER BALL MANDREL SELECTION CHART FITTING A WIPER DIE Marking on tube centreline Bend Die Clamp Die Pressure Die Mandrels Wiper Dies Hump at the end of a bend Deep scratches in bend/Wiper Die Area Tool marks on tube in clamp area Wrinkling in bend area Tube breakage in bending Tube collapses either with or without wrinkling through full bend Wrinkles on bend with all tools in correct position Excessive springback Selected according to tube OD (outside diameter) and CLR (centre line radius) requirements.
