Abstract: According to the present apparatus work pieces such as railroad wheels are power clamped on a cone shaped inwardly facing side. In a first clamping step clamping areas are impressed into the side or surface of the work piece said clamping areas having a suitable inclination. In a second clamping step the actual power clamping is performed at these clamping areas. For this purpose a plurality of radially moving clamping jaws are arranged to carry at least one clamping tooth. Each clamping tooth in turn is adjustable in its position in an axial direction along its respective radially moveable clamping jaw.

Abstract: A boring tool having a tool head rotatable about its axis and movable in direction of the axis along a working stroke and a return stroke. A knife having a pair of opposite cutting edges is floatingly mounted in a slot of the tool head extending transverse to the axis thereof and tiltable in the slot between a working position and a withdrawal position in which the cutting edges of the knife project a smaller distance beyond the periphery of the tool head than in the working position to prevent damage of the machined surface during the return stroke of the tool head.

Abstract: A combined tool for precision boring and burnishing the internal surfaces of workpieces comprises a bore head arrangement, a burnishing head arrangement rearwardly of the bore head arrangement and a feed tube arrangement connected to the burnishing head arrangement for axially advancing the latter and the bore head arrangement into a rotating workpiece for finishing the internal surface thereof while a stream of flushing oil under pressure is fed about the tool for removing chips shaved off by the bore head arrangement. The bore head arrangement is provided with a plurality of circumferentially displaced oil pockets which are supplied with oil under pressure for hydrostatically supporting and guiding the bore head arrangement during its advance.