Processes are disclosed for forming beryllium-copper metal rings having a fine and uniform grain structure. A raw BeCu casting is pre-forged and turned to form a BeCu billet. The BeCu billet is subjected to various heat treatment and cooling cycles to obtain/maintain combinations of advantageous material properties. Generally, the BeCu billet is preheated, hot worked via forging, heated again, hot worked again via ring rolling followed by air cooling, solution annealed followed by quenching, and heated a final time followed by air cooling.

An apparatus including a plurality of first and second pressing elements arranged in crown symmetrically around an axis of symmetry (B) so that a first end of a first pressing element cooperates in contact with a second end of a second pressing element; wherein the first and second pressing elements are supported slidingly and passing through by, respectively, a first and a second plate coupled and bound to each other, in respective second and first slits angularly spaced apart; the first pressing elements being provided with hammerheads circumferentially wider than the second slits and which cooperate circumferentially without play in contact with each other, and the second pressing elements being provided with engraving heads circumferentially wider than the first slits, which cooperate circumferentially without play in contact with each other.

The invention relates to a carburizing bearing steel and a preparation method thereof. The carburizing bearing steel of the invention comprises: 0.18˜0.24 wt % of C, 0.4˜0.6 wt % of Cr, 0.20˜0.40 wt % of Si, 0.40˜0.70 wt % of Mn, 1.6˜2.2 wt % of Ni, 0.15˜0.35 wt % of Mo, 0.001˜0.01 wt % of S, 0.001˜0.015 wt % of P, 0˜0.20 wt % of Nb, 0˜0.20 wt % of V and the remaining is iron, wherein the contents of Nb and V are not 0 at the same time. In the invention, an appropriate amount of Nb and V is added in combination with other elements so as to refine the grain size, inhibit the generation of large granular carbides in the steel during carburization and improve the uniformity of the microstructure of steel materials, thus further enhancing the contact fatigue life of the carburizing bearing steel.

A steering column for a motor vehicle may include a casing unit in which a steering spindle is mounted rotatably about a longitudinal axis that extends in a longitudinal direction. The casing unit has at least two casing tubes that have a polygonal cross section and are guided such that they can be adjusted relative to one another in the longitudinal direction. Rolling bodies that have a rolling body radius are arranged between the casing tubes such that the rolling bodies can roll in the longitudinal direction in at least three raceways that are distributed circumferentially. To increase rigidity and improve compactness, center points of the rolling bodies are at a radial spacing that is less than or equal to the rolling body radius from an envelope circle that circumscribes the casing tube, on which the rolling bodies can roll on the outside.

An apparatus including a plurality of first and second pressing elements arranged in crown symmetrically around an axis of symmetry (B) so that a first end of a first pressing element cooperates in contact with a second end of a second pressing element; wherein the first and second pressing elements are supported slidingly and passing through by, respectively, a first and a second plate coupled and bound to each other, in respective second and first slits angularly spaced apart; the first pressing elements being provided with hammerheads circumferentially wider than the second slits and which cooperate circumferentially without play in contact with each other, and the second pressing elements being provided with engraving heads circumferentially wider than the first slits, which cooperate circumferentially without play in contact with each other.

A bearing including a bearing sidewall including a first circumferential end including an apex region, and a second circumferential end including a nadir region, where the first circumferential end and the second circumferential end are adapted to contact each other to form an interface, where at least one of the apex region or the nadir region includes a void to prevent contact between the apex region of the first circumferential end and the nadir region of the second circumferential end, where the bearing sidewall includes a substrate and a low friction material, and where at least one of the first circumferential end or the second circumferential end comprises an end face that is free of low friction material.

A method for surface treatment of a workpiece includes providing the workpiece with hardened workpiece surface, clamping the workpiece, removing material from the hardened workpiece surface with a material removal tool to produce a machined surface with first machining tracks, and rolling the machined surface with a rolling tool by overlapping the first machining tracks to produce a rolled surface with second machining tracks. A distance between the material removal tool and the rolling tool measured in an axial direction of the workpiece is varied in an oscillating manner. The material removal tool may be advanced in the axial direction at a constant speed and the rolling tool may be advanced in the axial direction at an oscillating speed, or the rolling tool may be advanced in the axial direction at a constant speed and the material removal tool may be advanced in the axial direction at an oscillating speed.

A method of creating a roller bearing, comprising re-shaping a bearing ring blank utilizing cold impact intrusion, wherein the bearing ring blank includes a surface profile that forms at least one contour section within a contact side of the bearing ring upon the re-shaping, and wherein the contact side is configured to contact a support structure.

There is provided a hot rolled steel according to one aspect of the invention including, as a predetermined chemical composition: Bi: 0.0001 mass % to 0.0050 mass %, in which 90 area % or more of a metallographic structure is configured with a ferrite and a pearlite, and an average number density of Mn sulfides measured on a cross section parallel to a rolling direction having an aspect ratio of more than 10 and 30 or less which is extended along the rolling direction, is 50 pieces/mm.sup.2 to 200 pieces/mm.sup.2.

A manufacturing apparatus 1 has a leveler 3 which, while pulling out a steel plate starting with one end thereof and while transporting it, corrects the waviness and the like of the steel plate, which serves as a backing plate 2 and is constituted by a continuous strip having a thickness of 0.3 to 2.0 mm and provided as a hoop material by being wound into a coil shape.