Abstract: A tool for applying surface coated abrasives on a machine for abrasion machining of cylindrical bearing surfaces on workpieces such as crankshaft journals and crankpins comprises for each bearing surface to be machined a pivoted arm mobile vertically and three pads for applying surface coated abrasives. A first pad is mounted at a median top position on the arm and the other two at lateral bottom positions on two jaws articulated to the arm and coupled together so that they can be clamped together so that when clamped onto the bearing surface to be machined the three pads are disposed substantially at the three corners of an equilateral triangle. Each pad has a concave surface coated abrasive application surface subtending an angle of greater than 60.degree. so that after clamping the three pads of each arm enclose the bearing surface to be machined substantially completely.

Abstract: For the purpose of machining each journal (2,3) of the workpiece (1), the machine comprises three abrasive application blocks (13, 16a, 16b), one of which is mounted in a fixed position on the arm (7) and the other two are mounted on two jaws (14a, 14b) articulated on the arm (7), in such a way that, when the two jaws (14a, 14b) are clamped together, after the arm (7) has been lowered onto the journal to be machined, the three blocks (13, 16a, 16b) are arranged at the angles of an equilateral triangle and exert a uniform, controllable pressure on the workpiece (1).