A pliers for forming orthodontic wires has opposing beaks with complementary wire-forming surfaces that include interfering portions. A hinge mechanism enables the beaks to open and close by rotating about an axis, and also allows a range of axial motion between the beaks sufficient to prevent interference between the wire-forming surfaces as the beaks are closed. By preventing such interference, novel over-bending capabilities can be achieved to form useful bending of low spring rate wire. A spring, such as a Belleville washer, exerts a biasing force parallel to the hinge axis to maintain alignment of the beaks, but allows the required range of axial motion between the beaks to prevent interference.