Abstract: A predetermined composition is had, when a C content is represented by (C %), in a case of (C %) being not less than 0.35% nor more than 0.65%, a volume fraction of pearlite is 64×(C %)+52% or more, and in a case of (C %) being greater than 0.65% and 0.85% or less, the volume fraction of pearlite is not less than 94% nor more than 100%, and a structure of the other portion is composed of one or two of proeutectoid ferrite and bainite. Further, in a region to a depth of 1.0 mm from a surface, a volume fraction of pearlite block having an aspect ratio of 2.0 or more is not less than 70% nor more than 95%, and a volume fraction of pearlite having an angle between an axial direction and a lamellar direction on a cross section parallel to the axial direction of 40° or less is 60% or more with respect to all pearlite.

Abstract: Disclosed are a drill bit for drilling and a method for manufacturing same, in which the hardness of a body part of a shank can be selectively improved by performing rapid cooling in a forced cooling method after performing rapid heating selectively only on the body part of the shank in a high-frequency induction heating method after completing infiltration.

Abstract: Disclosed is a thermal reduction apparatus. The thermal reduction apparatus according to the exemplary embodiment includes: a preheating unit which preheats a to-be-reduced material and loads the to-be-reduced material into a reducing unit; the reducing unit which is connected to the preheating unit and in which a thermal reduction reaction of the to-be-reduced material occurs; a cooling unit which is connected to the reducing unit and from which the to-be-reduced material flowing into the cooling unit is unloaded to the outside; a gate device which is installed between the preheating unit and the reducing unit; a gate device which is installed between the reducing unit and the cooling unit; a condensing device which is connected to the reducing unit and condenses a metal vapor; a first blocking unit which is installed in the reducing unit; and a second blocking unit which is installed in the reducing unit so as to be spaced apart from the first blocking unit.

Abstract: A wire material used for manufacturing a non-heat treated component whose tensile strength is 900 MPa to 1300 MPa, containing, in mass %: C: 0.20% to 0.50%, Si: 0.05% to 2.0%, Mn: 0.20% to 1.0%, being limited to contain P: 0.030% or less, S: 0.030% or less, N: 0.005% or less, F1 defined by the following expression (1) is less than 0.60, with the balance made up of Fe and inevitable impurities, wherein a metal structure contains a pearlite structure of 64×(C %)+52% or more in a volume fraction, with the balance made up of one kind or two kinds of a pro-eutectoid ferrite structure and a bainite structure, an average block grain diameter of the pearlite structure at a region from a surface layer to 0.1 D is 15 ?m or less when a diameter of the wire material is set to be D, and (the average block grain diameter of the pearlite structure at the region from the surface layer to 0.1 D)/(an average block grain diameter of the pearlite structure at a range from 0.25 D to a center) is less than 1.0.

Abstract: A screw (1) having a head (2), a shaft (4) that includes a thread (5), and an interior engaging member (3) in the head is provided. The screw (1) is produced from an ultra-high strength steel using a cold forming method.

Abstract: A steel composition that includes: about 0.25-0.37% by weight Carbon; about 1.20-1.55% by weight Manganese; about 0.1-0.15% by weight Vanadium; about 0.20-0.40% by weight Nickel; about 0.20-0.50% by weight Silicon; about 0.30-0.45% by weight Copper; about 0.017-0.025% by weight Nitrogen; and Iron as the main constituent.

Abstract: The present invention provides a high strength bolt excellent in delayed fracture resistance able to advantageously prevent hydrogen embrittlement as represented by the delayed fracture phenomenon occurring along with an increase in strength and causing a particular problem, and a method of production of the same, containing, by mass %, C: 0.2 to 0.6%, Si: 0.05 to 0.5%, Mn: 0.1 to 2%, Mo: 0.5 to 6%, and Al: 0.005 to 0.5%, having a tensile strength of 1400 MPa or more, and having a compressive residual stress of the surface layer of the thread root of 10 to 90% of the tensile strength. Further, a surface layer part of the thread root from the surface down to at least 50 ?m has pre-austenite grains with an aspect ratio of the axial direction and radial direction of 2 or more and that part has a hardness of Hv 460 or more. Further, the method of production comprises using the steel material having the above ingredients to shape the bolt head and shaft, then heat the bolt to 900 to 1100° C.

Abstract: A method of manufacturing a blind threaded insert from metal which method comprises the steps of at least partially forming the insert, by a cold-forming process, other than the internal thread; forming the internal thread; and annealing the appropriate part of the insert to promote later deformation during installation.

Abstract: A high temperature bolt material, characterized in that it is a ferrite steel comprising 8 wt % or more of Cr and having a tempered martensite structure and can be used in a high temperature region of higher than 500° C.; and a method for producing the high temperature bolt material which comprises subjecting the above-mentioned steel material to a heat treatment comprising a quenching or normalizing at a temperature of 1000° C. or higher and then to a tempering at a temperature of 730° C. or higher. The above ferrite steel high temperature bolt material is excellent in characteristics of the resistance to stress relaxation.

Abstract: A formed product, characterized in that it is produced by using, as a material, a steel having an ultra fine structure comprising ferrite grains having an average grain diameter of 3 ?m or less and by a method comprising only a forming step and including none of refining steps; and a method for producting the above formed product with ease. The formed product contains no alloying element and has been subjected to no refining step, and has been imparted with high strength and high toughness by the above ultra fine structure.

Abstract: In a process for the production of a screw comprising a low-alloy carbon steel, having a head, an adjoining holding portion and a functional tip which, in the outer region of limited radial depth, is of a greater hardness than the holding portion, in which the screw body is shaped by pressing and rolling and then the functional tip is subjected to a hardening operation, hardening is effected by momentary heating with a high level of energy transfer and subsequent quenching and is limited to portions of the periphery of the functional tip.

Abstract: Steel wires and steel rods with excellent cold forging properties and used in a manufacture of various machine components, which have relatively high strengths, are disclosed. The steel wires are produced by maintaining a product (n×YS) of a yield strength (YS) and a work hardening coefficient (n) obtained by a tensile test of the steel wire within a range of 4.0-11.0 kgf/2, without a need of additional quenching and tempering treatments after cold forging. There is no need to perform heating for spheroidizing annealing for a long time, and it is possible to produce quenched and tempered steel wires having excellent cold forging properties by quenching and tempering treatments in a short period of time.

Abstract: A method of making a ball-screw rack bar for use in a power steering mechanism of an automotive vehicle. Transverse rack teeth are cut in an exterior surface of a first end portion of a length of a bar stock. A ball-screw thread is cut in an exterior surface of a second end portion of the length of bar stock. The first end portion is heat-treated to a first hardness and the second end portion is heat-treated to a second hardness by passing an induction coil scanner lengthwise over the length of bar stock from one end to the other. The ball-screw thread is cut by whirling. Preferably the heat-treating is carried out after the cutting of the transverse rack teeth and before the cutting of the ball-screw thread. The rack bar produced by this method may be solid or hollow. The rack bar may be made by separately forming two lengths of bar stock and butt-welding them together, or they may be made from a solid length of bar stock.

Abstract: A method of manufacturing a blind threaded insert from metal which method comprises the steps of at least partially forming the insert, by a cold-forming process, other than the internal thread; forming the internal thread; and annealing the appropriate part of the insert to promote later deformation during installation.

Abstract: A high-strength bolt having excellent delayed fracture resistance and stress relaxation resistance in addition to a tensile strength of 1200 N/mm2 or higher is disclosed. A steel material for the high-strength bolt includes C: 0.50 to 1.0% by mass (hereinafter, referred to simply as “%”), Si: 0.5% or less (not including 0%), Mn: 0.2 to 1%, P: 0.03% or less (including 0%) and S: 0.03% or less (including 0%). The steel material has pro-eutectoid ferrite, pro-eutectoid cementite, bainite and martensite structures at less than 20% in total and a pearlite structure as the remainder. The high-strength bolt is produced by drawing the steel material severely to obtain a steel wire, forming the steel wire into a bolt shape through a cold heading, and subjecting the shaped steel wire to a blueing treatment at a temperature within a range of 100 to 400° C.

Abstract: A method for cold forming a flattened, end-threaded rod into a U-bolt answers the need for high-strength steel rods that can be bent into flattened U-bolts by spring and suspension repair facilities or the like. By controlling the amount of work put into the end-threaded flattened rod during bending, it is possible to manufacture a flattened, end-threaded rod from a high-strength steel that can be successfully cold bent into a U-bolt. The amount or degree of flattening and the radius of the U-bolt are variables which applicant controls to successfully cold bend a high-strength steel flattened rod into a U-bolt. Therefore, the spring and suspension repair facility avoids the need to heat the flattened rods for warm forming and, instead, can maintain an inventory of end-threaded and flattened rods for cold forming into flattened U-bolt comply with OEM designs when modifying or repairing vehicles.

Abstract: A carbon steel screw has one or more portions which have been selectively hardened by selective heat treatment and quenching. In one embodiment, an upper portion of the screw head is selectively hardened to prevent or reduce damage when torque is applied using a driving tool. In another embodiment, the screw tip is selectively hardened for more effective penetration into a substrate. Preferably, the selectively heated portions are selectively quenched to reduce or avoid distortion.

Abstract: A ferrous-alloy aircraft structural component such as a fastener is prepared by providing a ferrous-alloy component precursor that is not in its final heat-treated state, and coating with an aluminum-containing, curable organic coating material having a non-volatile portion that is predominantly organic and is curable at about the ferrous-alloy component's tempering temperature. The coated, ferrous-alloy is then tempered to concurrently impart predetermined metallurgical properties to the finished, ferrous-alloy material, and cure the organic, aluminum-containing coating.

Abstract: A spiral parts heat treatment apparatus includes a first guide, a transfer unit, a second guide, and a controller. The first guide has a carrier portion that continuously conveys the manufactured spiral parts carried thereon in a longitudinal direction. The transfer unit is disposed downstream from the first guide to feed the spiral parts one by one after discrimination. The second guide is provided continuously to the transfer unit and has a carrier portion and a driving portion. The carrier portion serves to guide the spiral parts carried thereon in the longitudinal direction in the heat treatment furnace. The driving portion serves to push the spiral parts from a rear end side thereof and a driving portion. The controller performs a control operation so as to feed the spiral parts one by one.

Abstract: The present invention provides an outer ring for a high strength constant velocity joint which has an excellent torsional strength and torsional fatigue strength and can provide an improved processability, and a process for producing the same. An outer ring used for a high strength constant velocity joint having an involute serration part and a screw part, the outer ring made of a steel containing:C: 0.45 to 0.53%, Si: 0.05 to 0.25%, Mn: 0.7 to 1.0%, Al: 0.01 to 0.05%, Mo: 0.2 to 0.4%, N: 0.003 to 0.012%, the remainder being Fe and inevitable impurities, the inevitable impurities including:Cr: 0.05% or less than 0.05%, P: 0.015% or less than0.015%, S: 0.01% or less than 0.01%, and O: 0.002% orless than 0.002%,wherein an old austenite crystal grain at the involute serration end is 8 or more in JIS grain size classification; a surface hardness at the end is 720 or more in Hv; and a ratio (CD/R) is 0.35 to 0.

Abstract: A high-strength member of precipitation hardening martensitic steel is manufactured through the steps of heating precipitation hardening martensitic stainless steel at an austenitizing temperature, performing the first plastic working at a temperature between 200.degree. C. and 700.degree. C. so as to leave a part of austenite as retained austenite at the time of cooling the steel at Ms point or below thereafter, cooling the steel at the temperature not higher than Ms point, performing the next plastic working at a temperature not higher than As point so as to transform the retained austenite into martensite, and performing age hardening treatment at a temperature between not lower than 370.degree. C. and lower than 480.degree. C.

Abstract: An austenitic stainless steel screw having a nitride hard layer on its surface to prevent corrosion on parts of the screw such as a screw head which is in contact with the environment by removing a portion of the nitride hard layer to expose austenitic stainless steel base. By contrast, in the thread part and the like of the screw, the nitride hard layer is retained to improve the hardness and the tapping functions of the screw. In the method for manufacturing, the austenitic stainless steel screw is exposed to a fluorine-or fluoride-containing gas atmosphere prior to nitriding to form a fluoride film on its surface and then is nitrided in that state. Accordingly, the so formed nitride hard layer becomes uniform and deep to obtain an austenitic stainless steel screw having excellent surface properties.

Abstract: A method for manufacturing drill screws from austenitic stainless steel, which offers sufficient hardness for drilling and tapping into sheet iron and avoids the problems of intergranular corrosion and other erosions by taking full advantage of hardenability through cold working of austenitic stainless steel.The drill screw is manufactured by cold working from austenitic stainless steel. The above-mentioned material is formed into the head section (1) and shaft section (2) by header processing. The tip of the shaft section (2) is formed into the drill section (3) with the point (4), and with the cutting edge (5) running up to the tip. This is accomplished by pressing with a pair of pointer dies (7). On the die face (8), the cutting edge (9) and the receiving face (10) face each other. The shaft part (2) is formed into the screw part (6) by threading with a rolling die. Finally, all surface areas are passivated before aging treatment is applied.

Abstract: A method treating a surface of rotors in a screw-type rotary fluid machine, with the method comprising the steps of: conducting a non-electrolytic Ni plating on the surface of each rotor so as to form a first layer of non-electrolytic Ni plating layer; heating the rotor having the first layer at a temperature not lower than 500.degree. C.; and forming, at least, a second layer of an organic resin so as to cover the first layer.

Abstract: A method for manufacturing drill screws from austenitic stainless steel, which offers sufficient hardness for drilling and tapping into sheet iron and avoids the problems of intergranular corrosion and other erosions by taking full advantage of hardenability through cold working of austenitic stainless steel.The drill screw is manufactured by cold working from austenitic stainless steel. The above-mentioned material is formed into the head section (1) and shaft section (2) by header processing. The tip of the shaft section (2) is formed into the drill section (3) with the point (4), and with the cutting edge (5) running up to the tip. This is accomplished by pressing with a pair of pointer dies (7). On the die face (8), the cutting edge (9) and the receiving face (10) face each other. The shaft part (2) is formed into the screw part (6) by threading with a rolling die. Finally, all surface areas are passivated before aging treatment is applied.