A ball screw is provided in which an outer circumferential formation is formed at a portion facing a ball circulating passage out of outer circumferential surface of a nut. The ball screw includes: a screw shaft having on its outer circumferential surface a screw groove; a nut having on its inner circumferential surface a screw groove facing the screw groove; a plurality of balls rollably loaded in a spiral ball rolling passage formed by both screw grooves; and a ball circulating passage to return the balls from a start point to an end point of the ball rolling passage for recirculation. The ball circulating passage is a concaved groove formed by concaving a groove on a part of the cylindrical inner circumferential surface of the nut by plastic working. Then, a flange is integrally provided at a portion facing the ball circulating passage and the screw groove.

A method for manufacturing a gear toothing on a metallic workpiece and a tool device for calibration of a gear toothing inlet and/or a gear toothing outlet of a gear of the metallic workpiece. The method includes producing the gear toothing by forming manufacturing and performing a compression process to calibrate a gear toothing inlet and/or a gear toothing outlet of the gear toothing, wherein a gear tooth shape and a gear tooth length are adjusted during the compression process. The tool device includes a workpiece location for accommodating the workpiece, an axially movable die selectively engageable with the gear toothing, the die supporting the gear toothing and predefining the gear tooth shape to be adjusted on the gear toothing inlet and/or on the gear toothing outlet, and at least one axially movable compression ring which calibrates the gear toothing inlet and/or gear toothing outlet by a compression process.

A method for manufacturing a gear toothing on a metallic workpiece and a tool device for calibration of a gear toothing inlet and/or a gear toothing outlet of a gear of the metallic workpiece. The method includes producing the gear toothing by forming manufacturing and performing a compression process to calibrate a gear toothing inlet and/or a gear toothing outlet of the gear toothing, wherein a gear tooth shape and a gear tooth length are adjusted during the compression process. The tool device includes a workpiece location for accommodating the workpiece, an axially movable die selectively engageable with the gear toothing, the die supporting the gear toothing and predefining the gear tooth shape to be adjusted on the gear toothing inlet and/or on the gear toothing outlet, and at least one axially movable compression ring which calibrates the gear toothing inlet and/or gear toothing outlet by a compression process.

A forged crankshaft (1) includes a carbon steel containing S, wherein in a portion corresponding to a machined outer circumferential surface of a shaft part such as journals (J), crank pins (P), a front part (Fr), and a flange (Fl), a ratio x/y of an area rate x of sulfide in a position (X) corresponding to a parting surface of a die for finish forging to an area rate y of sulfide in a position (Y) corresponding to a bottom of a die impression of the die for finish forging is equal to or lower than 1.5. The forged crankshaft (1) can avoid an occurrence of machined surface cracks on the journals (J) and the crank pins (P) after the outer circumferential surface is machined.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

The invention discloses a process of manufacturing heavy and critical components such as a blowout preventer (BOP) with a combination of open die forging, piercing and machining process which results in to better material utilization and saving in the machining time. The forging process of the invention involves a step of notching, wherein a transverse notch is made near each end of the ingot before cogging said ingot. The invention allows development of safety and critical components with effective material utilisation.

The invention describes a method of manufacturing a substantially plate-shaped frame member (10) of a belt retractor including locking teeth (18). A plate-shaped element (24) is provided, wherein said element is plastically reshaped in portions so that a portion (28) thickened into a main portion (12) of the plate-shaped element (24) is formed. Furthermore, locking teeth (18) are produced in the thickened portion (28) so that the locking teeth (18) have a larger thickness than the plate-shaped element (24) prior to reshaping. Moreover, a frame member (10) for a belt retractor is described.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.