Abstract: In a threaded joint for steel pipes comprising a pin (1) and a box (2), each having a threaded portion (11 or 21), a sealing surface (13 or 23), and a shoulder surface (14, 15 or 24, 25), the sealing surface (13) of the pin (1) is formed by a tapered surface, and the sealing surface (23) of the box (2) is formed by a first curved surface portion with a large radius of curvature in the range of 15-120 mm, a tapered surface portion, and a second curved surface portion with a large radius of curvature again in the range of 15-120 mm.

Abstract: A threaded joint is constructed of a pin and a box. The pin includes, in order from an end thereof, a shoulder surface, a nose portion, a first sealing surface, a first male threaded portion, an annular portion, a second sealing surface, and a second male threaded portion. The box includes a shoulder surface, a recessed portion, a first sealing surface, a first female threaded portion, an annular portion, a second sealing surface, and a second female threaded portion. In the threaded joint, in a fastened state, the shoulder surfaces are in contact with each other, the first sealing surfaces are in contact with each other, the second sealing surfaces are in contact with each other, a clearance is provided between the nose portion and the recessed portion, a clearance is provided between the annular portions.

Abstract: A threaded tubular connection includes a female threaded portion at a first tubular component end and a male threaded portion at a second tubular component end, the female threaded portion including a female thread, at least one female sealing surface on its inner peripheral surface, and at least one female axial abutment surface, the male threaded portion including a male thread, at least one male sealing surface on its outer peripheral surface, at least one axial abutment surface, and a lip disposed between the sealing surface and an axial abutment surface located at a free end of the threaded portion distant from the thread, the male thread being made up into the female thread such that at least one male axial abutment surface is in contact with at least one female axial abutment surface, at least one male sealing surface being in interference contact with at least one corresponding female sealing surface, the portion of the lip between the sealing surface and the axial abutment surface being radially dist

Abstract: A threaded joint for steel pipes comprising a pin (1) and a box (2). The pin has a male thread (11) and a lip (12) which comprises (i) a sealing surface (13) and (ii) a nose portion (16) provided with a shoulder surface. The box has a female thread (21), a sealing surface (23) and a shoulder surface. The shoulder surface of the pin comprises two distinct adjacent surfaces, main shoulder (14) in the inner side and sub shoulder (15) in the outer side. Correspondingly, the shoulder surface of the box comprises two distinct adjacent surfaces, main shoulder (24) in the inner side and sub shoulder (25) in the outer side. The main shoulder surfaces of the pin and box are disposed such as to prevent a radially inward deformation of the lip end, and the sub shoulder surfaces of pin and box are disposed such as to limit a radially outward deformation of the lip end.

Abstract: A tire serving as an example of an aircraft tire includes a tread provided at intervals along a tire width direction with plural tire circumferential direction grooves that each extend along a tire circumferential direction with plural recessed portions provided in a groove bottom at intervals around the tire circumferential direction, wherein, from among plural land portions formed by the plural circumferential direction grooves, more of the recessed portions are disposed in first circumferential direction grooves that form a first land portion with a longest tire width direction length than in other second circumferential direction grooves.

Abstract: A threaded joint for pipes comprises a pin and a box, each having a threaded and unthreaded portion metal contact surface. The unthreaded metal contact portion includes a sealing surface and a shoulder surface, the shoulder surface of the pin located on the pin end surface. A non-contacting region where the pin and the box do not contact each other exists between the sealing surfaces and the shoulder surfaces of the pin and the box. One or more grooves is formed in at least one of the pin and the box shoulder surfaces and extending to the non-contacting region and to the interior of the joint. At least one of the contact surfaces has a solid lubricating coating exhibiting plastic or viscoplastic rheological behavior. A total volume V (mm3) of the grooves and coating weight W (g) of the solid lubricating coating satisfy the equation V/W?24 (mm3/g).

Abstract: A threaded joint for pipes comprises a pin and a box, each having a threaded and unthreaded portion metal contact surface. The unthreaded metal contact portion includes a sealing surface and a shoulder surface, the shoulder surface of the pin located on the pin end surface. A non-contacting region where the pin and the box do not contact each other exists between the sealing surfaces and the shoulder surfaces of the pin and the box. One or more grooves is formed in at least one of the pin and the box shoulder surfaces and extending to the non-contacting region and to the interior of the joint. At least one of the contact surfaces has a solid lubricating coating exhibiting plastic or viscoplastic rheological behavior. A total volume V (mm3) of the grooves and coating weight W (g) of the solid lubricating coating satisfy the equation V/W?24 (mm3/g).

Abstract: The present invention provides a tire in which generation of partial wear and groove cracks are suppressed.

Abstract: A threaded joint for steel pipes comprising a pin 1 having a tapered male thread 11, a tapered sealing surface 13, and an end shoulder surface 14 and a box 2 having correspondingly a tapered female thread 21, a tapered sealing surface 23, and a shoulder surface 24 which is capable of easy tightening and has improved air tightness by the sealing surfaces is arranged such that the pin and the box each have a noncontacting region B where the peripheral surfaces of the pin and the box do not contact each other between the sealing surfaces 13, 23 and the shoulder surfaces 14 and 24. At least a portion of the noncontacting region of the pin adjoining the to end of the pin is a tapered surface portion 18 having substantially the same angle of slope as the tapered sealing surface 13, and the noncontacting region of the box is a substantially cylindrical surface.

Abstract: In a threaded joint for steel pipes comprising a pin (1) and a box (2), each having a threaded portion (11 or 21), a sealing surface (13 or 23), and a shoulder surface (14, 15 or 24, 25), the sealing surface (13) of the pin (1) is formed by a tapered surface, and the sealing surface (23) of the box (2) is formed by a first curved surface portion with a large radius of curvature in the range of 15-120 mm, a tapered surface portion, and a second curved surface portion with a large radius of curvature again in the range of 15-120 mm.

Abstract: The present invention provides a tire in which generation of partial wear and groove cracks are suppressed.

Abstract: A threaded joint for steel pipes constituted by a pin having male threads and a box having female threads is improved with respect to ease of insertion of the pin and galling resistance of the threaded portions. The stabbing flanks of the threads in a complete thread portion of one of the pin and a box has a two-step stabbing shape having a chamfer. The two-step stabbing shape has a stabbing flank angle ? of 5-45° and a chamfer angle ? of 20-60°. The ratio h/H of the chamfer height h to the thread height H of the pin is 0.25-0.50, or the ratio of the cross-sectional area of the chamfered portion to the overall cross-sectional area of the stabbing flank is made at least a value corresponding to a chamfer height ratio h/H of 0.25 and at most a value corresponding to a chamfer height ratio of 0.50.

Abstract: A threaded joint for steel pipes comprising a pin (1) and a box (2). The pin has a male thread (11) and a lip (12) which comprises (i) a sealing surface (13) and (ii) a nose portion (16) provided with a shoulder surface. The box has a female thread (21), a sealing surface (23) and a shoulder surface. The shoulder surface of the pin comprises two distinct adjacent surfaces, main shoulder (14) in the inner side and sub shoulder (15) in the outer side. Correspondingly, the shoulder surface of the box comprises two distinct adjacent surfaces, main shoulder (24) in the inner side and sub shoulder (25) in the outer side. The main shoulder surfaces of the pin and box are disposed such as to prevent a radially inward deformation of the lip end, and the sub shoulder surfaces of pin and box are disposed such as to limit a radially outward deformation of the lip end.

Abstract: A threaded tubular connection includes a female threaded portion at a first tubular component end and a male threaded portion at a second tubular component end, the female threaded portion including a female thread, at least one female sealing surface on its inner peripheral surface, and at least one female axial abutment surface, the male threaded portion including a male thread, at least one male sealing surface on its outer peripheral surface, at least one axial abutment surface, and a lip disposed between the sealing surface and an axial abutment surface located at a free end of the threaded portion distant from the thread, the male thread being made up into the female thread such that at least one male axial abutment surface is in contact with at least one female axial abutment surface, at least one male sealing surface being in interference contact with at least one corresponding female sealing surface, the portion of the lip between the sealing surface and the axial abutment surface being radially dist

Abstract: A threaded joint for steel pipes comprising a pin 1 having a tapered male thread 11, a tapered sealing surface 13, and an end shoulder surface 14 and a box 2 having correspondingly a tapered female thread 21, a tapered sealing surface 23, and a shoulder surface 24 which is capable of easy tightening and has improved air tightness by the sealing surfaces is arranged such that the pin and the box each have a noncontacting region B where the peripheral surfaces of the pin and the box do not contact each other between the sealing surfaces 13, 23 and the shoulder surfaces 14 and 24. At least a portion of the noncontacting region of the pin adjoining the to end of the pin is a tapered surface portion 18 having substantially the same angle of slope as the tapered sealing surface 13, and the noncontacting region of the box is a substantially cylindrical surface.