Abstract: A driving tool includes: a striking unit striking a fastener by being actuated in a first direction; a rack on the striking unit; a wheel; and a second transmission portion on the wheel and capable of being engaged with and released from the rack. The striking unit can be actuated in a second direction when the second transmission portion is engaged with the rack, and the striking unit can be actuated in the first direction when the second transmission portion is released from the rack. The second transmission portion includes: a tooth portion arranged along a rotation direction of the wheel and turned in a predetermined direction to be engaged with and released from the rack; and a movable piece actuated in the predetermined direction to be engaged with the rack and actuated in a different direction from the predetermined direction to be released from the rack.

Abstract: There is provided a steel sheet having a chemical composition comprising, in mass %, C: 0.05 to 0.25%, Si: 0.2 to 2.0%, Mn: 1.2 to 3.0%, P: 0.030% or less, S: 0.050% or less, Al: 0.01 to 0.55%, N: 0.0100% or less, and Ti: 0.010 to 0.250%, with the balance: Fe and impurities, wherein a random intensity ratio of a texture in a near-surface portion of the steel sheet is 8.0 or less, and a minimum angle formed between a maximum strength orientation in a {110} pole figure of the texture and a normal direction of a rolled surface of the steel sheet is 10° or less.

Abstract: A shearing method of a plate-shaped workpiece for applying a shear force in a thickness direction of the plate-shaped workpiece includes: a step for starting applying the shear force on the workpiece with a clearance between action points in a surface direction orthogonal to the thickness direction of the workpiece; a step for applying the shear force after the start of applying the shear force until a fractured surface is created in the workpiece; and a step for increasing the clearance depending on a deformation of the workpiece in the thickness direction after starting applying the shear force until the fractured surface is created in the workpiece.

Abstract: This steel sheet has a predetermined chemical composition, has a microstructure in which a number density of alloy carbides present at grain boundaries and having a major axis of 10 to 100 nm is 1.0×108 to 1.0×1011/cm2 and a number density of alloy carbides present in grains and having a major axis of 10 nm or less is 1.0×1016 to 1.0×1019/cm3, and has a tensile strength of 1,030 MPa or more.

Abstract: This steel sheet has predetermined chemical composition and microstructure, in a crystal orientation distribution function of a texture at a sheet thickness ¼ position, when A/B that is a ratio of a maximum value A of pole densities at ?=20° to 60° and ?1=30° to 90° in a cross section of ?2=45° to a maximum value B of pole densities at ?=120° to 60° and ?1=30° to 90° in the cross section of ?2=45° is 1.50 or less, a total of the maximum value A and the maximum value B is 6.00 or less, and a tensile strength is 1030 MPa or more.

Abstract: This steel sheet is a steel sheet (100) formed by causing end surfaces of a first sheet material (111) and a second sheet material (113) to abut each other in an in-plane direction and welding the first sheet material (111) and the second sheet material (113) via a strip-shaped welded part (115), and in which a softened part (120) that is softened more than other parts in the welded part (115) is formed in at least a part of the welded part (115), and on a first end surface of the steel sheet in which an end part of the welded part (115) in a longitudinal direction is formed, a region in which the softened part (120) is not formed is provided in at least a part of the end part of the welded part (115) in the longitudinal direction, and a maximum value of a depth of the softened part (120) in a sheet thickness direction is, as a ratio to a sheet thickness of the steel sheet (100), 50% or less.

Abstract: A shearing method of a plate-shaped workpiece for applying a shear force in a thickness direction of the plate-shaped workpiece includes: a step for starting applying the shear force on the workpiece with a clearance between action points in a surface direction orthogonal to the thickness direction of the workpiece; a step for applying the shear force after the start of applying the shear force until a fractured surface is created in the workpiece; and a step for increasing the clearance depending on a deformation of the workpiece in the thickness direction after starting applying the shear force until the fractured surface is created in the workpiece.

Abstract: Provided is a steel sheet comprising a sheet thickness center part and a first surface layer softened part and a second surface layer softened part respectively arranged at two sides of the sheet thickness center part, wherein the first surface layer softened part and second surface layer softened part have 10 ?m or more average thicknesses and have average Vickers hardnesses of 0.90 time or less of the average Vickers hardness of a sheet thickness ½ position, and the first surface layer softened part has an average Vickers hardness of 1.05 times or more the average Vickers hardness of the second surface layer softened part.

Abstract: Provided is a steel sheet comprising a sheet thickness center part and a first surface layer part and a second surface layer part respectively arranged at two sides of the sheet thickness center part, wherein the first surface layer part and second surface layer part respectively independently have thicknesses of more than 10 ?m to 30% or less of the sheet thickness, the first surface layer part and second surface layer part have average Vickers hardnesses different from the average Vickers hardness of a sheet thickness ½ position, and a first hardness cumulative value at a region from a surface of the first surface layer part side to 30% of the sheet thickness is 1.05 times or more of a second hardness cumulative value at a region from a surface of the second surface layer part side to 30% of the sheet thickness.

Abstract: This hot-rolled steel sheet has a predetermined chemical composition and predetermined metallographic structure, a ratio between a maximum depth of a region where, on one surface, a rotation angle between a normal line of the one surface and a (011) pole near the normal line of the one surface is 5° or less and a maximum depth of a region where, on the other surface, a rotation angle between a normal line of the other surface and a (011) pole near the normal line of the other surface is 5° or less is 1.00 to 1.20, and a tensile strength is 1150 MPa or more.

Abstract: Adopted are a hot-rolled steel sheet having a predetermined chemical composition, in which a region, where a rotation angle between a normal line of a surface and a (011) pole near the normal line becomes 5° or less, is 0.150 or less from the surface in terms of a sheet thickness direction position standardized by a sheet thickness, and a region, where the rotation angle becomes 20° or more, is 0.250 or more from the surface in terms of the sheet thickness direction position standardized by the sheet thickness and a manufacturing method thereof.

Abstract: According to one aspect of the present invention, there is provided a T-joint including a first steel sheet, a second steel sheet, and a fillet welded part, in which the sheet thickness of the second steel sheet is 6.0 mm or less, the second steel sheet is stood on a first surface of the first steel sheet, the fillet welded part joins the first surface of the first steel sheet and a first surface of the second steel sheet to each other, at least one of the first surface of the first steel sheet or the first surface of the second steel sheet includes a zinc-based plating, an abutting end portion of the second steel sheet on a second surface side of the second steel sheet has an inclined surface, and in a cross section taken along a sheet thickness direction of the first steel sheet and a sheet thickness direction of the second steel sheet, the inclined surface forms an acute angle with respect to the first surface of the first steel sheet.

Abstract: There is provided a cutting method for cutting a workpiece using a cutting tool comprising a die and a punch, including: arranging the workpiece between the die and the punch, and in a state in which a wedge-shaped first cutting part of the die and a wedge-shaped second cutting part of the punch are opposed, pushing the punch relatively to the die side to cut the workpiece; wherein: a front end angle ?1 of the first cutting part and a front end angle ?2 of the second cutting part are each 100 or more and 1200 or less, and a front end radius R1 of the first cutting part and a front end radius R2 of the second cutting part are each 0.5% or more and 35.0% or less of a sheet thickness.

Abstract: The present invention has as its technical problem to provide a punching method able to stably secure a stretch-flangeability equal to or greater than the case of using a punch having a flat blade at its bottom surface. The punching method of the present invention is a method of punching a metal sheet using a punching and shearing device provided with a punch having an upper blade having a horizontal part with respect to the cutting line in part and having parts other than the horizontal part comprised of inclined parts and a die having a lower blade wherein the upper blade used for the punching process has a shape where the inclined parts first contact the metal sheet at the time of a punching process.

Abstract: A blank (100) includes a main portion (110) that is made of steel having a tensile strength of 1450 MPa or more and a softened portion (120), the ratio of Vickers hardness of the softened portion (120) to the Vickers hardness of the main portion (110) is 0.7 or more and 0.95 or less, and the softened portion (120) is disposed at a position different from a position of the main portion (110) in an in-plane direction. A structural member (200) includes a first member (210), a second member (220), and a weld (W) at which the first member (210) and the second member (220) are welded to each other.

Abstract: This steel sheet is a steel sheet (100) formed by causing end surfaces of a first sheet material (111) and a second sheet material (113) to abut each other in an in-plane direction and welding the first sheet material (111) and the second sheet material (113) via a strip-shaped welded part (115), and in which a softened part (120) that is softened more than other parts in the welded part (115) is formed in at least a part of the welded part (115), and on a first end surface of the steel sheet in which an end part of the welded part (115) in a longitudinal direction is formed, a region in which the softened part (120) is not formed is provided in at least a part of the end part of the welded part (115) in the longitudinal direction, and a maximum value of a depth of the softened part (120) in a sheet thickness direction is, as a ratio to a sheet thickness of the steel sheet (100), 50% or less.

Abstract: A cutting method using a stamping press according to the present disclosure is a method to cut a workpiece that is configured from a first metal sheet and a second metal sheet joined at a weld portion and that has a heat-affected zone around the weld portion, in which the workpiece is cut using a punch. The punch includes a flat portion and a projecting portion projected more toward the workpiece than a flat portion of the punch. The workpiece is positioned with respect to the punch at a position such that the projecting portion starts cutting at least at one out of the heat-affected zone or the weld portion before the flat portion cuts the workpiece. The workpiece is then cut by moving the punch and a die relative to each other in this state of positioning so as to shear across the weld portion on the workpiece.

Abstract: There is provided a hole widening method including a preparing process of preparing a forming tool which has a diameter-increasing portion increasing in diameter from a front end side toward a rear end side and a line-shaped projection formed to protrude outward from a surface of the diameter-increasing portion, and a workpiece in which a pilot hole is formed; and a hole widening process of successively widening the pilot hole by pushing the forming tool into the pilot hole such that the line-shaped projection of the forming tool comes into point contact with a part of a circumferential edge portion of the pilot hole in the workpiece two times or more, and forming a stretched flange.

Abstract: In a breaking prediction method of predicting a breaking portion of a component, which is obtained by forming a metal sheet, by using a finite element method, the breaking portion is easily and reliably extracted.

Abstract: The present invention provides a method for shear processing whereby a sheared surface having a small residual stress and excellent surface properties is formed and the service life of a punch is prolonged in a shear processing for shearing, by a shear line that crosses a weld zone, a workpiece with a large thickness of level difference of a weld zone and/or obtained by welding together a steel sheet having a strength of 1000 MPa or more and another steel sheet. The shearing for shear processing method according to the present invention is a method for shearing a workpiece having a weld zone using a punch and a die, the method characterized in that two protrusions are provided to a cutting edge of the punch, all or part of the weld zone of the workpiece is flanked from the two sides by the two protrusions, and the workpiece is sheared by a shear line that crosses the weld zone.