Abstract: A tube support mandrel for use with a multiaxis tube bender acts to support the outer surface, rather than the inner surface, of the tube, and so may be used with tubes that are open on one side, or which otherwise do not have a complete, enclosed interior. In the disclosed embodiment, the mandrel includes a stack of thin steel plates, each of which has a central hole that matches the outer surface of the tube. A partially urethane overmold encases and retains the plates together with the central holes aligned. When the tube is forced through the bender, it passes through the aligned plate holes, which closely confine and support its cross sectional shape while flexing to accommodate the curvature being bent into it.