A tubular connection comprising a longitudinal axis, a pin member comprising a distal pin end, a tapered pin thread having a constant pin taper angle α.sub.1 with respect to the longitudinal axis, and a pin sealing surface located between the pin thread and the distal pin end, and a box member comprising a distal box end, a box sealing surface, and a tapered box thread having a constant box taper angle β.sub.1 with respect to the longitudinal axis and located between the box sealing surface and the distal box end, and wherein the pin thread is configured to cooperate by make up with the box thread along a cooperating area, while having a radial thread interference between the pin thread and the box thread along at least part of the cooperating area, the pin sealing surface and the box sealing surface are configured to contact each other upon make-up in a sealing manner while forming a metal to metal seal, and the pin taper angle α.sub.1 is larger than the box taper angle β.sub.1.

A tubular connection comprising a longitudinal axis, a pin member comprising a distal pin end, a tapered pin thread having a constant pin taper angle α.sub.1 with respect to the longitudinal axis, and a pin sealing surface located between the pin thread and the distal pin end, and a box member comprising a distal box end, a box sealing surface, and a tapered box thread having a constant box taper angle β.sub.1 with respect to the longitudinal axis and located between the box sealing surface and the distal box end, and wherein the pin thread is configured to cooperate by make up with the box thread along a cooperating area, while having a radial thread interference between the pin thread and the box thread along at least part of the cooperating area, the pin sealing surface and the box sealing surface are configured to contact each other upon make-up in a sealing manner while forming a metal to metal seal, and the pin taper angle α.sub.1 is larger than the box taper angle β.sub.1.

A threaded connection for steel pipe is provided that can be made up quickly and appropriately. The threaded connection includes a steel pipe 20m, a steel pipe 20f, and a coupling 50 for connecting the steel pipes 20m and 20f. The pipe bodies 21m and 21f of the steel pipes 20m and 20f include annular marking grooves 23m and 23f, respectively, formed on the outer peripheries of the pipe bodies 21m and 21f.

A threaded connection for steel pipe is provided that can be made up quickly and appropriately. The threaded connection includes a steel pipe 20m, a steel pipe 20f, and a coupling 50 for connecting the steel pipes 20m and 20f. The pipe bodies 21m and 21f of the steel pipes 20m and 20f include annular marking grooves 23m and 23f, respectively, formed on the outer peripheries of the pipe bodies 21m and 21f.

A threaded connection between adjacent drill string components comprises a threaded female connection end adapted to receive a correspondingly threaded male connection end, the two ends each having first and second portions of different tapers. Tubular members, drill string tools and other drill string components comprising the female or male ends described herein are also provided.

A threaded connection between adjacent drill string components comprises a threaded female connection end adapted to receive a correspondingly threaded male connection end, the two ends each having first and second portions of different tapers. Tubular members, drill string tools and other drill string components comprising the female or male ends described herein are also provided.

An apparatus comprising an inner ferrule and an outer ferrule. The inner ferrule comprises a plurality of engagement sections that define a plurality of gaps between the plurality of engagement sections. The outer ferrule is disposed around at least a portion of the inner ferrule. The outer ferrule comprises an engagement area mechanically joined to the plurality of engagement sections to join the inner ferrule to the outer ferrule.

A screw joint in which an efficient screw length of a joint portion is achieved. This screw joint is for an oil well pipe of an integral type and includes: (i) a pin that is provided with a male screw portion which is a male taper screw, at one end of a steel pipe; and (ii) a box that is provided with a female screw portion which is a female taper screw fitted to the male screw portion, at one end of the steel pipe, in which a structure, in which the pin and the box are in metal contact with each other to seal a fluid, is provided at least at one place of a seal portion on an outer peripheral surface side of a pipe end side of the pin and a seal portion on an inner peripheral surface side of a pipe end side of the box.

A pipe fitting having a first body and a second body that together at least partially define a fluid flow passage. The first body defines a first portion of the fluid flow passage that extends from a first end of the fluid flow passage to a first internal opening. The second body defines a second portion of the fluid flow passage that extends from a second internal opening to a second end of the fluid flow passage. The first body has a first interface surface that surrounds the first internal opening, the first interface surface having a plurality of anti-rotation grooves. The second body has a second interface surface that surrounds the second internal opening and engages with the first interface surface. The first internal opening is in fluid communication with the second internal opening. The second interface surface has a plurality of anti-rotation fingers that are each received by and engage with a corresponding one of the anti-rotation grooves. Rotation of the second body relative to the first body is resisted by the engagement of the anti-rotation fingers with the anti-rotation grooves.

A pipe fitting having a first body and a second body that together at least partially define a fluid flow passage. The first body defines a first portion of the fluid flow passage that extends from a first end of the fluid flow passage to a first internal opening. The second body defines a second portion of the fluid flow passage that extends from a second internal opening to a second end of the fluid flow passage. The first body has a first interface surface that surrounds the first internal opening, the first interface surface having a plurality of anti-rotation grooves. The second body has a second interface surface that surrounds the second internal opening and engages with the first interface surface. The first internal opening is in fluid communication with the second internal opening. The second interface surface has a plurality of anti-rotation fingers that are each received by and engage with a corresponding one of the anti-rotation grooves. Rotation of the second body relative to the first body is resisted by the engagement of the anti-rotation fingers with the anti-rotation grooves.