A method produces an inner spiral grooved tube using a first drawing die, a second drawing die, and a revolving flyer. The method includes two twisting-drawing steps. The first twisting-drawing step forms an intermediate twisted tube by reducing the diameter of a linear grooved tube, which has plural straight grooves formed along the longitudinal direction on its inner surface, by passing the linear grooved tube through the first drawing die and then by revolving the liner grooved tube wrapped around the revolving flyer with the revolving flyer, in conjunction with imparting twist to the linear grooved tube. The second twisting-drawing step forms the inner spiral grooved tube by reducing the diameter of the intermediate twisted tube by passing the intermediate twisted tube, which revolves with the revolving flyer, through the second drawing die in conjunction with imparting twist to the intermediate twisted tube.

A steam generator pipe for producing a steam generator pipe with a spiral-shaped installation body, wherein an elevation extends on the inner side of the steam generation pipe in the axial direction of the steam generator pipe. A method for producing a steam generator pipe having an installation body.

A steam generator pipe for producing a steam generator pipe with a spiral-shaped installation body, wherein an elevation extends on the inner side of the steam generation pipe in the axial direction of the steam generator pipe. A method for producing a steam generator pipe having an installation body.

A method produces an inner spiral grooved tube using a first drawing die, a second drawing die, and a revolving flyer. The method includes two twisting-drawing steps. The first twisting-drawing step forms an intermediate twisted tube by reducing the diameter of a linear grooved tube, which has plural straight grooves formed along the longitudinal direction on its inner surface, by passing the linear grooved tube through the first drawing die and then by revolving the liner grooved tube wrapped around the revolving flyer with the revolving flyer, in conjunction with imparting twist to the linear grooved tube. The second twisting-drawing step forms the inner spiral grooved tube by reducing the diameter of the intermediate twisted tube by passing the intermediate twisted tube, which revolves with the revolving flyer, through the second drawing die in conjunction with imparting twist to the intermediate twisted tube.

A method produces an inner spiral grooved tube using a first drawing die, a second drawing die, and a revolving flyer. The method includes two twisting-drawing steps. The first twisting-drawing step forms an intermediate twisted tube by reducing the diameter of a linear grooved tube, which has plural straight grooves formed along the longitudinal direction on its inner surface, by passing the linear grooved tube through the first drawing die and then by revolving the liner grooved tube wrapped around the revolving flyer with the revolving flyer, in conjunction with imparting twist to the linear grooved tube. The second twisting-drawing step forms the inner spiral grooved tube by reducing the diameter of the intermediate twisted tube by passing the intermediate twisted tube, which revolves with the revolving flyer, through the second drawing die in conjunction with imparting twist to the intermediate twisted tube.

A pipe body, wherein the pipe body (10) has a welded portion (11) at both ends of the pipe body, aligned in a widthwise direction of the pipe body (10). The thickness of the welded portion (11) decreases gradually from the inside to the outside of the pipe, and an outer end of the welded portion (11) is located at a center portion of the pipe body (10) in a thickness direction. The configuration of the welding structure enhances the strength of the welded portion of the pipe, so that the pipe will not crack easily when it is reworked by flaring or bending, thus having high reworkability. In addition, a pipe (100) made of the pipe body (10) and a method of making the pipe (100) are disclosed.

A metallic ingot for impact pressing includes a contact surface of the metallic ingot to contact a male mold in impact pressing having a maximum height roughness Rz of 20 m to 50 m and an average length of a roughness curve element RSm of 150 m to 400 m, the male mold being to be used in combination with a female mold in the impact pressing.

A metallic ingot for impact pressing includes a contact surface of the metallic ingot to contact a male mold in impact pressing having a maximum height roughness Rz of 20 m to 50 m and an average length of a roughness curve element RSm of 150 m to 400 m, the male mold being to be used in combination with a female mold in the impact pressing.

A metallic ingot for impact pressing includes a contact surface of the metallic ingot to contact a male mold in impact pressing having a maximum height roughness Rz of 20 m to 50 m and an average length of a roughness curve element RSm of 150 m to 400 m, the male mold being to be used in combination with a female mold in the impact pressing.

A metallic ingot for impact pressing includes a contact surface of the metallic ingot to contact a male mold in impact pressing having a maximum height roughness Rz of 20 m to 50 m and an average length of a roughness curve element RSm of 150 m to 400 m, the male mold being to be used in combination with a female mold in the impact pressing.