Abstract: A tool for rasping comprising a cylindrical drum rotatable in both directions around an axis, the drum being equipped with cutting elements which protrude exteriorly and are able to act in the two directions of rotation. The cutting elements are mounted on a series of movable bars disposed on the exterior surface of the drum parallel to the axis, each one of these bars having at least one transverse row of cutting elements. Each cutting element of a same row displays two parallel cutting edges provided at opposite acute angles with respect to the axis of the drum. The cutting elements of each of the rows present cutting edges which are essentially equal to those of adjacent rows but oppositely directed. The bars possess means for quick assembly onto the drum. The tool is used in preparing the exterior surface of a tire for retreading.

Abstract: A new cutting plate with a chip-breaker on at least one of the working faces, the plate being triangular or quadrilateral, with a preferably zero or positive back clearance and with a cutting angle which may generally be of any size but preferably positive. The plate is characterized in that the back clearance angle .delta. and cutting angle .eta. are obtained from cutting surfaces which are portions of conical surfaces with axes perpendicular to the plane Q.sub..gamma. containing the main cutting points, that the cutting edge comprises at least one arc of a curve, representing the intersection between at least one cone and the plane Q .alpha., and that the cutting surface adjoining a cutting point, comprising two consecutive surface elements joined along an arc of a curve in the plane bisecting the cutting point, causing discontinuity in the lines of level, is such that the cutting angle decreases as the plane No approaches the cutting point.

Abstract: The invention relates to a guide roller for hot-rolling mills for long metallurgical products and to the method by which it is made. The roller consists of a hollow core and an annular ring mounted on the core. The core is generally fabricated from soft metals, such as aluminum or magnesium and alloys thereof readily worked by conventional forming techniques while the ring consists of a hard refractory material, such as a metallic carbide, nitride, carbonitride or boride or a ceramic based on metal oxides.

Abstract: A small polygonal shaped cutting plate designed to be secured onto the body of a tool for machining of metal pieces, presenting at least one rectilinear cutting edge, containing a groove assuring unrolling and control of the cutting, as well as a radiating cutting point characterized by the fact that it is composed of:A. a cutting surface with an essentially pyramidal shape whose generatrices form a constant angle with a base plane Qo containing the cutting edge, andB. an assembly of planes forming another surface called the chip breaker on which the shaving to be broken butts in such a manner that a hollow zone is formed in the radiating cutting point whose lowest point is situated in the bisector plane of the cutting point.

Abstract: A detachable cutting plate which is of polygonal, equilateral, but not equiangular, shape and designed for centerless descaling of rough-drawn or rough-rolled materials, by radial mounting on a rotary multi-tool head, characterized in that it comprises along each main cutting edge two adjoining chip-breaking surfaces consisting of separate concave grooves; (a) the first facing the straight part of the main cutting edge, of which the axis directing the surface is parallel with the said edge and forming a cutting angle .alpha..sub.1 ; (b) the second facing the curved part of the edge connecting the main cutting edge to the secondary planing edge having a directing axis perpendicular to the plane bisecting the curved cutting part and forming a cutting angle .alpha..sub.2.