Abstract: A high strength cold-rolled steel sheet has excellent surface appearance and a composition consisting essentially of, in mass %, C: 0.0005-0.025%, Si: at most 0.2%, Mn: 0.3-2.5%, P: at most 0.15%, S: at most 0.02%, N: at most 0.006%, sol. Al: less than 0.005%, Ti: 0.005-0.05%, and Nb: 0.020-0.200% with the mass ratio (Nb/Ti) of the contents of Nb and Ti being at least 2, either boron at most 0.0020% or one or more of Cr, Mo, V, W, Cu, and Ni, each at most 1%, and a remainder of Fe and impurities. The sheet has excellent press formability and tensile strength by having an r value in a direction at 45° with respect to the rolling direction (r45) of at least 1.80 and/or a mean r value (rm) of at least 1.60, and a tensile strength of at least 340 MPa.

Abstract: A high strength cold-rolled steel sheet has excellent surface appearance and a composition consisting essentially of, in mass %, C: 0.0005-0.025%, Si: at most 0.2%, Mn: 0.3-2.5%, P: at most 0.15%, S: at most 0.02%, N: at most 0.006%, sol. Al: less than 0.005%, Ti: 0.005-0.05%, and Nb: 0.020-0.200% with the mass ratio (Nb/Ti) of the contents of Nb and Ti being at least 2, either boron at most 0.0020% or one or more of Cr, Mo, V, W, Cu, and Ni, each at most 1%, and a remainder of Fe and impurities. The sheet has excellent press formability and tensile strength by having an r value in a direction at 45° with respect to the rolling direction (r45) of at least 1.80 and/or a mean r value (rm) of at least 1.60, and a tensile strength of at least 340 MPa.

Abstract: A high strength cold-rolled steel sheet and a high strength plated steel sheet which have an excellent surface appearance required for outer panels of automobiles and which have an extremely high r value in a direction at 45° with respect to the rolling direction and which have excellent press formability and a tensile strength of at least 340 MPa and a process for their manufacture are provided. The steel sheets have a chemical composition consisting essentially of, in mass %, C: 0.0005-0.025%, Si: at most 0.2%, Mn: 0.3-2.5%, P: at most 0.15%, S: at most 0.02%, N: at most 0.006%, sol. Al: less than 0.005%, Ti: 0.005-0.05%, and Nb: 0.020-0.200% with the mass ratio (Nb/Ti) of the contents of Nb and Ti being at least 2, and a remainder of Fe and impurities, and they have an r value in a direction at 45° with respect to the rolling direction (r45) of at least 1.80 and/or a mean r value (rm) of at least 1.60, and a tensile strength of at least 340 MPa.

Abstract: A high strength cold-rolled steel sheet and a high strength plated steel sheet which have an excellent surface appearance required for outer panels of automobiles and which have an extremely high r value in a direction at 45° with respect to the rolling direction and which have excellent press formability and a tensile strength of at least 340 MPa and a process for their manufacture are provided. The steel sheets have a chemical composition consisting essentially of, in mass %, C: 0.0005-0.025%, Si: at most 0.2%, Mn: 0.3-2.5%, P: at most 0.15%, S: at most 0.02%, N: at most 0.006%, sol. Al: less than 0.005%, Ti: 0.005-0.05%, and Nb: 0.020-0.200% with the mass ratio (Nb/Ti) of the contents of Nb and Ti being at least 2, and a remainder of Fe and impurities, and they have an r value in a direction at 45° with respect to the rolling direction (r45) of at least 1.80 and/or a mean r value (0 of at least 1.60, and a tensile strength of at least 340 MPa.

Abstract: A machine tool includes a table supported by a bed for forward and rearward movement along a path of movement, left and right transversely aligned upright columns on opposite sides of the path of movement, a cross rail supported in the columns for movement upwardly and downwardly along forward and rear guide rails on inwardly facing column surfaces, a spindle head supported by the cross rail for movement leftwardly and rightwardly. The cross rail, the left and right columns, the spindle head and the guide rails are symmetrically positioned from front to rear and vertically by vertical or horizontal symmetry defining planes so that heat generated creates balanced self-cancelling forces.

Abstract: A machine tool comprises a table 12 supported by a bed 11 forwardly and rearwardly movably, a pair of left and right columns 13 provided upright on opposite sides of a path of movement of the table, a cross rail 14 supported by the columns 13 upwardly and downwardly movably, and a spindle head 15 supported by the cross rail 14 leftwardly and rightwardly movably. With respect to the front-rear direction, the columns 13 have centerlines in alignment with each other, i.e., a centerline L. The cross rail 14 has a centerline N with respect to the front-rear direction. The cross rail 14 is moved upward and downward with the column centerline L with respect to the front-rear direction in alignment with the rail centerline N with respect to the front-rear direction.

Abstract: An attachment (5) is detachably mounted on the lower end of a main shaft ram (4) in such a manner that the attachment (5) can rotate about horizontal and vertical axes. The power line of a motor installed in the attachment (5) is inserted through a pair of flexible tubes (13, 25) with its ends connected to a terminal box of the attachment (5) and a terminal box (29) of the main shaft ram (4). The flexible tubes (13, 25) have a pair of connectors (15, 26) which are coupled to each other by a coupling mechanism (27) when the attachment (5) is mounted on the main shaft ram (4). A drum (30) and a rodless cylinder 32 provided above the connector (26) constitute a mechanism (36) for lifting the flexible tubes (13, 25). When the rotation of the attachment (5) about either or both of the axes causes slack in the flexible tube (13), the lifting mechanism (36) eliminate the slack bay pulling up the drum (30) and thus the flexible tube (25).