Abstract: A bending die for forming a 180.degree. bend in a tube includes a center die and a shiftable block pivotally mounted to the center die grooves are defined on opposing sides of the center die and shiftable block for supporting the tube while being bent. The grooves have a C-shaped cross section for receiving and holding the tube during the bending process, but which grooves create an interference condition trapping the bent tube in a plane defined by the grooves. The shiftable block is pivotally connected to the center die and movable between a bend-forming position where the shiftable block forms an upper part of the groove along the one opposing side and part of the end, and a tube-release position where the shiftable block is removed from the one opposing side. The bending die also includes a clamp die that both clamps the tube to the center die and also holds the shiftable block to the center die while the tube is being bent, but which is movable to release the shiftable block.