Abstract: A fastener to fasten a member to be fastened includes a shaft portion, a tool working surface, and an external operation restricting portion. The shaft portion is provided with a male thread configured to be rotated about an axis line to work so as to fasten the member to be fastened. The tool working surface is formed to a tool working portion integrated with the shaft portion. A tool to rotate the shaft portion works to the tool working surface. The external operation restricting portion is configured to restrict the rotation of the shaft portion through an operation from outside the fastener. In this fastener, the tool working surface to which the tool works is formed in an approximately cylindrical inner surface shape.

Abstract: A fastener to fasten a member to be fastened includes a shaft portion, a tool working surface, and an external operation restricting portion. The shaft portion is provided with a male thread configured to be rotated about an axis line to work so as to fasten the member to be fastened. The tool working surface is formed to a tool working portion integrated with the shaft portion. A tool to rotate the shaft portion works to the tool working surface. The external operation restricting portion is configured to restrict the rotation of the shaft portion through an operation from outside the fastener. In this fastener, the tool working surface to which the tool works is formed in an approximately cylindrical inner surface shape.

Abstract: A light-emitting device is provided whose color mixing property and light emission efficiency are improved, while white light with high color rendering performance is ensured by means of four kinds of LED elements emitting red, green, blue, and white light respectively.

Abstract: A light-emitting device is provided whose color mixing property and light emission efficiency are improved, while white light with high color rendering performance is ensured by means of four kinds of LED elements emitting red, green, blue, and white light respectively.

Abstract: Provided is a duplex stainless steel having a high strength and a high toughness. A stainless steel according to the present invention includes: a chemical composition containing, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: at least 0.50% and less than 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities; and a structure, wherein a rate of ferrite in the structure is 30 to 70%, and a hardness of the ferrite in the structure is at least 300 Hv10gf.

Abstract: A welded joint of duplex stainless steel, which can suppress precipitation ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments. A weld metal of the welded joint contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: at most 2.00%, Ni: 7.00 to 12.00%, Cr: 20.0 to 30.0%, Mo: 1 to 4%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, and O: at most 0.035%, the balance being Fe and impurities. The weld metal satisfies Expressions (1) and (3): 2.2Cr+7Mo+3Cu>66??(1) Cr+11Mo+10Ni?12(Cu+30N)<100??(3) where a content (mass percent) of each element in one of the base metal and weld metal is used for each element in Expressions (1) and (3).

Abstract: A process for producing a welded joint, which includes a weld metal having high strength and high toughness, and containing fewer blowholes, includes the steps of: preparing a base material containing, by mass %, not less than 10.5% of Cr; and subjecting the base material to GMA welding using a shielding gas containing 1 to 2 volume % or 35 to 50 volume % of CO2 gas, and the balance being inert gas, thereby forming a weld metal includes, by mass %, C: not more than 0.080%, Si: 0.20 to 1.00%, Mn: not more than 8.00%, P: not more than 0.040%, S: not more than 0.0100%, Cu: not more than 2.0%, Cr: 20.0 to 30.0%, Ni: 7.00 to 12.00%, N: 0.100 to 0.350%, O: 0.02 to 0.11%, sol. Al: not more than 0.040%, at least one of Mo: 1.00 to 4.00% and W: 1.00 to 4.00%, and the balance being Fe and impurities.

Abstract: A self-tapping screw for soft metals having low required initial driving torque, high axial force in the tightened state, small axial force reduction due to heat or the like, and a low manufacturing cost because no intricate and expensive mold is required, and also has an advantage that an amount of produced chip powder is small. The self-tapping screw includes a tapered smaller diameter part at an end of a shaft. The smaller diameter part is inserted and driven into a pilot hole formed in a soft metal to form a female screw in the pilot hole. In the shaft and the smaller diameter part, a continuous male screw with a constant pitch is formed.

Abstract: Provided is a self-tapping screw for soft metals that features low required initial driving torque, high axial force in the tightened state, small axial force reduction due to heat or the like, and a low manufacturing cost because no intricate and expensive mold is required, and also has an advantage that an amount of produced chip powder is small. The self-tapping screw includes a tapered smaller diameter part 3 at an end of a shaft 2. The smaller diameter part 3 is inserted and driven into a pilot hole formed in a soft metal to form a female screw in the pilot hole. In the shaft 2 and the smaller diameter part 3, a continuous male screw with a constant pitch is formed.

Abstract: Provided is a process for producing a welded joint which includes a weld metal having high strength and high toughness, and containing fewer blowholes. The process for producing a welded joint according to the present embodiment includes the steps of: preparing a base material containing, by mass %, not less than 10.5% of Cr; and subjecting the base material to GMA welding using a shielding gas containing 1 to 2 volume % or 35 to 50 volume % of CO2 gas, and the balance being inert gas, thereby forming a weld metal includes, by mass %, C: not more than 0.080%, Si: 0.20 to 1.00%, Mn: not more than 8.00%, P: not more than 0.040%, S: not more than 0.0100%, Cu: not more than 2.0%, Cr: 20.0 to 30.0%, Ni: 7.00 to 12.00%, N: 0.100 to 0.350%, O: 0.02 to 0.11%, sol. Al: not more, than 0.040%, at least one of Mo: 1.00 to 4.00% and W: 1.00 to 4.00%, and the balance being Fe and impurities.

Abstract: Provided is a duplex stainless steel having a high strength and a high toughness. A stainless steel according to the present invention includes: a chemical composition containing, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: at least 0.50% and less than 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities; and a structure, wherein a rate of ferrite in the structure is 30 to 70%, and a hardness of the ferrite in the structure is at least 300 Hv10gf.

Abstract: A duplex stainless steel, which can suppress precipitation of a ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments and has a high strength. The duplex stainless steel includes a chemical composition containing, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 28.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities, and satisfying Expression (1) and Expression (2); a structure having a ferrite rate of at least 50%; and a yield strength of at least 550 MPa or more: 2.

Abstract: A welded joint of duplex stainless steel, which can suppress precipitation of ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments. A weld metal of the welded joint contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: at most 2.00%, Ni: 7.00 to 12.00%, Cr: 20.0 to 30.0%, Mo: 1 to 4%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, and O: at most 0.035%, the balance being Fe and impurities. The weld metal satisfies Expressions (1) and (3): 2.2Cr+7Mo+3Cu>66??(1) Cr+11Mo+10Ni?12(Cu+30N)<100??(3) where a content (mass percent) of each element in one of the base metal and weld metal is used for each element in Expressions (1) and (3).

Abstract: A method of making an UOE steel pipe having excellent deformability and low-temperature toughness includes providing a steel composition with a controlled composition consisting essentially of C: 0.03-0.07%, Si: 0.05-0.50%, Mn: 1.6-2.2%, P: at most 0.020%, S: at most 0.003%, Cu: 0.20-0.60%, Cr: at most 0.10%, Ni: 0.20-0.80%, Nb: 0.005-0.030%, Ti: 0.005-0.030%, N: at most 0.0070%, Al: 0.005-0.060%, and a remainder of Fe and impurities, a hardenability index Pcm of at most 0.22%, Cu+Cr+Ni is 0.4-1.5%, and Nb+Mo+V is at most 0.05%. The pipe has a yield strength in the longitudinal direction of at least 480 MPa, a yield-tensile ratio of at most 85% and a Charpy absorbed energy of the heat affected zone at ?40° C. of at least 40 J.

Abstract: In a high-tensile steel plate according to the invention, the carbon equivalent Pcm represented in Expression (1) is from 0.180% to 0.220%, the surface hardness is a Vicker's hardness of 285 or less, the ratio of a Martensite Austenite constituent in the surface layer is not more than 10%, the ratio of a mixed structure of ferrite and bainite inside beyond the surface layer is not less than 90%, the ratio of the bainite in the mixed structure is not less than 10%, the thickness of the lath of bainite is not more than 1 ?m, the length of the lath is not more than 20 ?m, and the segregation ratio as the ratio of the Mn concentration in the center segregation part relative to the Mn concentration at a part in a depth equal to ¼ of the thickness of the plate from the surface is not more than 1.3. Pcm=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5B . . . (1) where the element symbols in Expression (1) represent the % by mass of the respective elements.

Abstract: A high-strength UOE steel pipe which has excellent deformability and excellent low-temperature toughness in its heat affected zone and which is suitable for use in a pipeline installed on permafrost in extremely cold regions or in earthquake-prone regions, for example, is provided. The UOE steel pipe has a steel composition consisting essentially of C: 0.03-0.07%, Si: 0.05-0.50%, Mn: 1.6-2.2%, P: at most 0.020%, S: at most 0.003%, Cu: 0.20-0.60%, Cr: at most 0.10%, Ni: 0.20-0.80%, Nb: 0.005-0.030%, Ti: 0.005-0.030%, N: at most 0.0070%, Al: 0.005-0.060%, and a remainder of Fe and impurities, the hardenability index Pcm is at most 0.22%, Cu+Cr+Ni is 0.4-1.5%, Nb+Mo+V is at most 0.05%. The pipe has a yield strength in the longitudinal direction of at least 480 MPa with a yield-tensile ratio of at most 85% and a Charpy absorbed energy of the heat affected zone at ?40° C. of at least 40 J.

Abstract: In order to provide a high tensile strength steel having excellent low temperature toughness and which can withstand large heat input welding, a steel comprises, in mass percent, C: 0.01-0.10%, Si: at most 0.5%, Mn: 0.8-1.8%, P: at most 0.020%, S: at most 0.01%, Cu: 0.8-1.5%, Ni: 0.2-1.5%, Al: 0.001-0.05%, N: 0.0030-0.0080%, O: 0.0005-0.0035%, if necessary at least one of Ti: 0.005-0.03%, Nb: 0.003-0.03%, and Mo: 0.1-0.8%, and a remainder of Fe and impurities, and the N/Al ratio is 0.3-3.0.

Abstract: A bent pipe corresponding to at least API X100 grade and having a base metal with high strength and toughness and a weld metal with high toughness is provided. A steel plate prepared by cooling after hot rolling at a cooling rate at the central portion in the plate thickness direction of at most 5° C. per second at 700-500° C. is formed into a bend mother pipe, which is then heated to 900-1100° C. and subjected to bending, then it is cooled to a temperature of at most 300° C. at a cooling rate in the central portion of the thickness direction of at least 5° C. per second at 700-500° C., after which it is tempered at 300-500° C.

Abstract: A high-strength hot bend pipe which has a balance between an excellent strength of at least X70 grade and toughness and which has excellent tensile properties and a weld metal with excellent low temperature toughness is manufactured. A UOE steel pipe having a base metal with a composition of C: 0.03-0.12%, Si: 0.05-0.50%, Mn: 1.4-2.2%, S: at most 0.01%, Al: at most 0.06%, N: at most 0.008%, and a remainder of Fe and impurities, with the carbon equivalent (Ceq) being at most 0.36% and the weld cracking parameter (Pcm) being at most 0.22%, and having a weld metal with a weld cracking parameter (Pcm) of at most 0.28%, a B content of at most 5 ppm, and an O content of at most 280 ppm is heated to a temperature range of 900-1100° C. and subjected to bending, and then is immediately cooled to a temperature range of 300° C. or lower at a cooling rate of at least 3° C./sec, and then is tempered in a temperature range of 300-500° C.