The high-strength steel for steel forgings according to the present invention has a composition that includes, as basic components, C: 0.35 mass % to 0.47 mass %; Si: 0 mass % to 0.4 mass %; Mn: 0.6 mass % to 1.5 mass %; Ni: more than 0 mass % up to 2.0 mass %; Cr: 0.8 mass % to 2.5 mass %; Mo: 0.10 mass % to 0.7 mass %; V: 0.035 mass % to 0.20 mass %; Al: 0.015 mass % to 0.050 mass %; N: 30 ppm to 100 ppm, and O: more than 0 ppm up to 30 ppm, the balance being Fe and inevitable impurities. The metal structure is mainly bainite, martensite or a mixed structure of bainite and martensite. Among cubic B1-type precipitates, the number of coherent precipitates having a diameter equal to or smaller than 30 nm is equal to or smaller than 50/m.sup.2.

The high-strength steel for steel forgings according to the present invention has a composition that includes, as basic components, C: 0.35 mass % to 0.47 mass %; Si: 0 mass % to 0.4 mass %; Mn: 0.6 mass % to 1.5 mass %; Ni: more than 0 mass % up to 2.0 mass %; Cr: 0.8 mass % to 2.5 mass %; Mo: 0.10 mass % to 0.7 mass %; V: 0.035 mass % to 0.20 mass %; Al: 0.015 mass % to 0.050 mass %; N: 30 ppm to 100 ppm, and O: more than 0 ppm up to 30 ppm, the balance being Fe and inevitable impurities. The metal structure is mainly bainite, martensite or a mixed structure of bainite and martensite. Among cubic B1-type precipitates, the number of coherent precipitates having a diameter equal to or smaller than 30 nm is equal to or smaller than 50/m.sup.2.

A method of producing a press-formed product includes a steel plate heating step, a hot forging step and a hot stamping step. In the steel plate heating step, a steel plate is heated to 950 C. or more. In the hot forging step, the heated steel plate is forged to form a varying-thickness steel plate. In the hot stamping step, the heated varying-thickness steel plate is subjected to press-working by a press tooling to form a press-formed product, and the press-formed product that is formed is cooled inside the press tooling. Thus, a press-formed product that has high strength and for which a reduction in weight is possible can be produced.

A method for making a blind hole may include arranging a workpiece in a negative form with a first portion and a second portion. The first portion may include a recess. The second portion may include a guide for a punch. The recess may be arranged substantially coaxially to the guide. The method may also include displacing a material of the workpiece into the recess via pressing the punch into the workpiece. Additionally, the method may include pressing the punch into the workpiece in a first movement section with a first velocity. The method may further include further pressing the punch into the workpiece in a second movement section with a second velocity such that the material is sheared and is partly extruded into the recess. The method may include moving the first portion relative to the second portion and shearing off the material displaced within the recess.

A method and apparatus for enabling handgun magazines to function in a rifle lower forging, may include a rifle lower forging. The rifle lower forging may include but is not limited to a recessed area on a side portion of the rifle lower forging configured to receive a handgun magazine release. The rifle lower forging may further include a vertical hole on a top portion of the rifle lower forging configured to receive an elongated portion to hold the handgun magazine release. The rifle lower forging may further include a hole perpendicular to the vertical hole configured to receive a handgun magazine release spring. The rifle lower forging may further include a horizontal slit on the top portion of the rifle lower forging configured to receive an ejector. The rifle lower forging may further include one or more apertures perpendicular to the horizontal slit each configured to receive a fastener to secure the ejector to the rifle lower forging. The rifle lower forging may further include a hollow portion proximate the horizontal slit configured to receive a handgun magazine.

A power end frame assembly for a reciprocating pump that includes a first and second end plate segment each including annular bearing support surfaces configured to support a crankshaft bearing assembly. At least one middle plate segment is disposed between the first and second end plate segments and includes an annular bearing support surface configured to support a crankshaft bearing assembly. The annular bearing support surfaces of the first and second end plate segments and the at least one middle plate segment each have a diameter and are coaxially aligned. The diameter of at least one of the first and second end plate segments is different from the diameter of the at least one middle plate segment to facilitate insertion and removal of the crankshaft bearing assembly from the power end frame assembly.

A power end frame assembly for a reciprocating pump that includes a first and second end plate segment each including annular bearing support surfaces configured to support a crankshaft bearing assembly. At least one middle plate segment is disposed between the first and second end plate segments and includes an annular bearing support surface configured to support a crankshaft bearing assembly. The annular bearing support surfaces of the first and second end plate segments and the at least one middle plate segment each have a diameter and are coaxially aligned. The diameter of at least one of the first and second end plate segments is different from the diameter of the at least one middle plate segment to facilitate insertion and removal of the crankshaft bearing assembly from the power end frame assembly.

A manufacturing method of a metal member includes performing first shaving on a first surface perpendicular to a thickness direction of a metal plate, in a first portion of the metal plate by moving a cutting edge in a direction along the first surface. In the metal plate, the thickness of the first portion is reduced to be smaller than the thickness of a second portion by the first shaving.

A method for texturizing a workpiece uses a die assembly installed within a press having a press ram. The method includes (a) delivering the workpiece onto a center die plate; (b) forcing the press ram against an upper die plate mounted above the center die plate to descend a first contact surface associated with the upper die plate and a plurality of blades mounted to the upper die plate toward the center die plate; (c) actuating horizontal movement of the blades; (d) driving the blades down into the workpiece; and (e) contacting the first contact surface to a second contact surface associated with the center die plate to descend the center die plate in unison with the upper die plate.

A method for texturizing a workpiece uses a die assembly installed within a press having a press ram. The method includes (a) delivering the workpiece onto a center die plate; (b) forcing the press ram against an upper die plate mounted above the center die plate to descend a first contact surface associated with the upper die plate and a plurality of blades mounted to the upper die plate toward the center die plate; (c) actuating horizontal movement of the blades; (d) driving the blades down into the workpiece; and (e) contacting the first contact surface to a second contact surface associated with the center die plate to descend the center die plate in unison with the upper die plate.