A roughly shaped material for a rolling bearing of the present invention is produced by forging a steel composed of a high-carbon chrome bearing steel containing 0.7 mass % to 1.2 mass % of a carbon, and 0.8 mass % to 1.8 mass % of a chromium to a predetermined shape while heating the steel to a forging temperature in a range of (Ae.sub.1 point+25 C.) to (Ae.sub.1 point+105 C.), cooling a forged article to a temperature of Ae.sub.1 point or lower, and performing an annealing in which the forged article that is obtained is heated to a soaking temperature in a range of (Ae.sub.1 point+25 C.) to (Ae.sub.1 point+85 C.), the forged article is retained for 0.5 hours or longer, and the forged article is cooled down to 700 C. or lower at a cooling rate of 0.30 C./s or slower.

Provided is a method for manufacturing a bearing ring member, whereby processing cost can be reduced and a high degree of freedom in design is obtained, by disposing a metal material of a raw material (13a), the metal material having excellent metal characteristics such as fatigue strength and wear resistance and excellent processing characteristics such as hardenability, in a portion that flows to a portion (raceway surface, etc.) where the characteristics of the metal material are required during use or forging of a bearing ring member. The present invention is configured from a first metal part (23) in which the raw material (13a) is formed in a cylindrical shape, and a second metal part (24) formed in a columnar shape by a metal material having more excellent metal characteristics or processing characteristics than the first metal part (23). For example, the second metal part (24) is disposed in a portion on an inside diameter side of the first metal part (23), which is a portion of the raw material (13a) that flows to an outer raceway (5a, 5b) of an outer ring (2) during forging.

Provided is a method for manufacturing a bearing ring member, whereby processing cost can be reduced and a high degree of freedom in design is obtained, by disposing a metal material of a raw material (13a), the metal material having excellent metal characteristics such as fatigue strength and wear resistance and excellent processing characteristics such as hardenability, in a portion that flows to a portion (raceway surface, etc.) where the characteristics of the metal material are required during use or forging of a bearing ring member. The present invention is configured from a first metal part (23) in which the raw material (13a) is formed in a cylindrical shape, and a second metal part (24) formed in a columnar shape by a metal material having more excellent metal characteristics or processing characteristics than the first metal part (23). For example, the second metal part (24) is disposed in a portion on an inside diameter side of the first metal part (23), which is a portion of the raw material (13a) that flows to an outer raceway (5a, 5b) of an outer ring (2) during forging.

A method of manufacturing a recirculating ball nut for a ball screw drive, comprising a base body which includes at least one recirculating ball track, the method comprising the following manufacturing steps: manufacturing the base body by precision forging; and finishing the recirculating ball track by a cutting method subsequent to manufacturing the base body.

A method of manufacturing a recirculating ball nut for a ball screw drive, comprising a base body which includes at least one recirculating ball track, the method comprising the following manufacturing steps: manufacturing the base body by precision forging; and finishing the recirculating ball track by a cutting method subsequent to manufacturing the base body.

In a method for producing a ring-shaped formed part, by means of a forming device first of all a ring of smaller cross-sectional dimensions than the formed part being produced is formed from a blank in various forming stages. The ring is then expanded to the cross-sectional dimensions of the formed part being produced. The expansion of the ring is effected in an expansion stage of the forming device by means of a die and an expansion punch, where the ring is arranged in the die and the expansion punch is pressed into the ring in the axial direction and thereby expands the ring. The expansion of the ring is effected in two or more steps. In that way, excessive material stresses and any resulting material damage can be avoided.

In a method for producing a ring-shaped formed part, by means of a forming device first of all a ring of smaller cross-sectional dimensions than the formed part being produced is formed from a blank in various forming stages. The ring is then expanded to the cross-sectional dimensions of the formed part being produced. The expansion of the ring is effected in an expansion stage of the forming device by means of a die and an expansion punch, where the ring is arranged in the die and the expansion punch is pressed into the ring in the axial direction and thereby expands the ring. The expansion of the ring is effected in two or more steps. In that way, excessive material stresses and any resulting material damage can be avoided.

A near-net shape forming method for fabricating the precise bearing ring forging is invented. The processing method is composed of following three procedures. (1) the precise ring-like billet with chamfer angle is manufactured by the machining method. (2) The billet is heated by the less oxidation or non-oxidation heating method before ring rolling. (3) The bearing ring forging integrating with the raceway is formed in one pass of the rolling process by the ring rolling method.

A near-net shape forming method for fabricating the precise bearing ring forging is invented. The processing method is composed of following three procedures. (1) the precise ring-like billet with chamfer angle is manufactured by the machining method. (2) The billet is heated by the less oxidation or non-oxidation heating method before ring rolling. (3) The bearing ring forging integrating with the raceway is formed in one pass of the rolling process by the ring rolling method.

Provided is a method for manufacturing a tubular rotary component from a donut-shaped metal disc, wherein the generation of wrinkles or cracks due to a drawing process can be suppressed. This method for manufacturing a tubular rotary component 100B includes: an intermediate molding step in which the entirety of both surfaces of a donut-shaped metal disc 100 having a prescribed inner diameter D.sub.1 and outer diameter D.sub.2 are pressed by the respective tapered surfaces of a punch 10A and a die 20A provided with a prescribed taper to carry out bore-expansion drawing, thereby obtaining a frustoconical intermediate molded article 100A; and a final molding step in which the intermediate molded article 100A is pressed by a punch 10B and a die 20B having a desired shape to carry out bore-expansion drawing again, thereby obtaining a tubular rotary component 100B.