Abstract: A threaded joint for steel pipes comprises a pin (1) and a box (2). The pin has male thread (11), a sealing surface (13), and a shoulder surface (14) located on the end face of the pin. Correspondingly, the box has female thread (21), a sealing surface (23), and a shoulder surface (24) which can mate or contact with the corresponding portions of the pin. The shoulder surface (14) of the pin (1) is provided at an end face of the pin. The sealing surface (13) of the pin (1) is located on a pipe end side near the male thread (11). A a nose portion (15) is provided on the pin (1) between the sealing surface (13) and the shoulder surface (14), the nose portion (15) being not in contact with a corresponding portion of the box (2).

Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.

Abstract: A tubular threaded joint which has excellent resistance to compression and which permits easy tightening operation in the field in a vertical state comprises a pin having a male threaded zone and a box having a female threaded zone. The pin or the box has an end shoulder surface on its end, and the other member has a shoulder surface which abuts against the end shoulder surface. The screw threads of the male threaded zone and the female threaded zone are trapezoidal threads having a crest, a load flank, and a stabbing flank. The lip length, which is the distance in the axial direction of a member having an end shoulder surface between the end shoulder surface and the closest engaged thread to that surface, is at least 140 times the stabbing flank clearance, which is the distance in the axial direction between the stabbing flanks of the male thread and the female thread when the load flanks of the male and female threads contact each other. The stabbing flank of the male thread is preferably chamfered.

Abstract: A tubular threaded joint which has excellent resistance to compression and which permits easy tightening operation in the field in a vertical state comprises a pin having a male threaded zone and a box having a female threaded zone. The pin or the box has an end shoulder surface on its end, and the other member has a shoulder surface which abuts against the end shoulder surface. The screw threads of the male threaded zone and the female threaded zone are trapezoidal threads having a crest, a load flank, and a stabbing flank. The lip length, which is the distance in the axial direction of a member having an end shoulder surface between the end shoulder surface and the closest engaged thread to that surface, is at least 140 times the stabbing flank clearance, which is the distance in the axial direction between the stabbing flanks of the male thread and the female thread when the load flanks of the male and female threads contact each other. The stabbing flank of the male thread is preferably chamfered.

Abstract: In a threaded joint for steel pipes which are connected by threaded engagement of a pin member having a tapered male thread, a metal seal-forming portion, and a torque shoulder-forming portion on the end of a pipe, and a box member having a tapered female thread, a metal seal-forming portion, and a torque shoulder forming-portion corresponding to these on the end of a pipe, a buttress thread having contact at the load flanks and the thread root surface and gaps at the thread crest surface and the stabbing flanks is mixed in a single joint with a rugged thread having contact at the load flanks and stabbing flanks and having gaps at the thread root surface and thread crest surface.

Abstract: In a threaded joint for steel pipes which are connected by threaded engagement of a pin member having a tapered male thread, a metal seal-forming portion, and a torque shoulder-forming portion on the end of a pipe, and a box member having a tapered female thread, a metal seal-forming portion, and a torque shoulder forming-portion corresponding to these on the end of a pipe, a buttress thread having contact at the load flanks and the thread root surface and gaps at the thread crest surface and the stabbing flanks is mixed in a single joint with a rugged thread having contact at the load flanks and stabbing flanks and having gaps at the thread root surface and thread crest surface.

Abstract: A threaded joint for steel pipes comprises a pin (1) and a box (2). The pin has male thread (11), a sealing surface (13), and a shoulder surface (14) located on the end face of the pin. Correspondingly, the box has female thread (21), a sealing surface (23), and a shoulder surface (24) which can mate or contact with the corresponding portions of the pin. The shoulder surface (14) of the pin (1) is provided at an end face of the pin. The sealing surface (13) of the pin (1) is located on a pipe end side near the male thread (11). A a nose portion (15) is provided on the pin (1) between the sealing surface (13) and the shoulder surface (14), the nose portion (15) being not in contact with a corresponding portion of the box (2).

Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.

Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.

Abstract: A male threaded joint tipped with a male lip having a male seating face and a male stop transverse surface proximate to the male seating face. A female threaded element includes for co-operation with the corresponding male threaded element, a female seating face and a female stop transverse surface provided on a female shoulder and proximate to the female seating face. The annular female shoulder zone is subjected to axial compression forces resulting from the pressure of the male and female stop surfaces and has an inner peripheral surface, the diameter of which is at least locally proximate to the female stop surface smaller than the diameter of the inner peripheral surface of the male lip. The ratio R of the two diameters is less than 1 but not less than 0.9.

Abstract: In a method for verifying a timing at an object logic cell between a first signal and a second signal in a logic circuit with a plurality of logic cells including the object logic cell, there are determined first delay data of the first signal from a first external input terminal to the object logic cell, first waveform slew data of the first signal to the object logic cell and first signal data indicating a frequency, duty ratio and jitter of the first signal and a second waveform slew data of the second signal to the object logic cell. A first portion of a first waveform of the first signal and a second portion of a second waveform of the second signal is calculated in time then it is determined whether the first portion of the first waveform overlaps the second portion of the second waveform.

Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: 1 C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.

Abstract: The invention concerns a male threaded joint (1) tipped with a male lip (18) having a male seating face (13) and a male stop (14) transverse surface (16) proximate to the male seating face; and a female threaded element (21) comprising, for co-operation with the corresponding means of the male threaded element a female seating face (23) and a female stop transverse surface provided on a female shoulder and proximate to the female seating face. The annular female shoulder zone (24) which is subjected to axial compression forces resulting from the pressure of the male (16) and female (26) stop surfaces have an inner peripheral surface (27) whereof the diameter (IDB) is at least locally proximate to said female stop surface (26) smaller than the diameter (IDP) of the inner peripheral surface (17) of the male lip (18), the ratio R of said two diameters (IDB/IDP) being less than 1 but not less than 0.9.

Abstract: In a method for verifying a timing at an object logic cell between a first signal and a second signal in a logic circuit with a plurality of logic cells including the object logic cell, there are determined first delay data of the first signal from a first external input terminal to the object logic cell, first waveform slew data of the first signal to the object logic cell and first signal data indicating a frequency, duty ratio and jitter of the first signal and a second waveform slew data of the second signal to the object logic cell. A first portion of a first waveform of the first signal at the object logic cell is calculated in time based on the first delay data, and the first waveform slew data and the first signal data a second portion of a second waveform of the second signal at the object logic cell is calculated in time based on the second waveform slew data. Then, it is determined whether the first portion of the first waveform overlaps the second portion of the second waveform.

Abstract: [Purpose] To provide a threaded connection capable of preventing deterioration of gas tightness from occurring when a tensile stress acts thereon after a compressive force in the direction of the axis of a pipe is applied. [Means of Solving Problems] (1) A threaded connection for oil country tubular goods wherein a length (15) of a thick walled portion with a diameter defined in the formula (1), is longer than the length (16) from seal contact to the extremist of the pin section, shorter than a half of the length (17) of the pin section, the rest of inside diameter is equal to the inside diameter of pipe proper, having smooth tapered inner wall between thick walled portion and pipe proper. The inside diameter of the box section of torque shoulder section is the same as inside diameter of thick wall. d0>dx≧d0−6 mm  (1) Where dx(mm)=inside diameter of the thick walled portion of the pin section, and d0(mm)=inside diameter of the pipe proper.

Abstract: A threaded connection for the oil country tubular goods, according to the invention, is provided with either an internal shoulder or an external shoulder or both, each comprising a seal portion and a torque shoulder, and characterized by satisfying the following conditions (1) and (2):(1) A pitch diameter of the seal forming face on the pin is larger than the same on the box; and(2) An inclination of the torque shoulder forming face on the pin is smaller than the same on the box, the difference in the inclination between the both sides being in the range of 0.5 to 4.0.degree..The threaded connection for the oil country tubular goods, according to the invention, has excellent gas tightness and crevice corrosion resistance. Moreover, the production cost thereof is equivalent to that of conventional threaded connections and it is easy to handle.

Abstract: A threaded joint for an oil well pipe having (1) a tapered threaded having roughly the shape of a buttress thread, (2) a pin having a male thread and a box having a female thread, (3) a seal and a torque shoulder, characterized in that(i) the load flank angle of the threads is -20.degree. or greater and less than 0.degree.,the stab flank angle is greater than 30.degree. and at most 60.degree.(ii) there is a positive amount of interference between the male threads and the female threads, and(iii) during and at the completion of make-up, the load flanks and the stab flanks are contacting each other, and there is a gap between the crests and the roots.

Abstract: A threaded joint for oil well pipes has excellent leak-tightness and a high disconnect torque and can withstand repeated make-ups. At the time of make-up, the load flanks (1) of the male and female threads contact each other, either the crest surfaces (3) or the root surfaces (4) are contacting and the other of the two pairs of surfaces has a gap, and a gap of at most 0.03 mm exists between the stab flanks (2) of the male and female threads.