MANUFACTURING METHOD OF THREADED COUPLING FOR CASING PIPES AND TUBING STRINGS Russian patent published in 2015 - IPC B23Q3/00 

FIELD: oil and gas industry.

SUBSTANCE: manufacturing method of a threaded coupling for casing pipes and tubing strings, which is provided on each of its ends with a threaded element in the form of an internal conical thread, involves fixation of a tubular workpiece in a spindle chuck of a turning machine, its rotation in the above chuck, turning processing of the inner surface of the first threaded element on one end of the workpiece and the second threaded element on the other end of the workpiece by a cutting tool installed in a turret head and moved relative to the frame of the turning machine. For processing of the second threaded element, the second spindle is used, and processing of outer and inner surfaces of the first threaded element and cutting of the internal conical thread is performed in the workpiece with an unprocessed outer surface. After processing of the first threaded element in the first spindle is completed, the second spindle is supplied to the workpiece being processed; the workpiece is clamped in the second spindle chuck using its smooth processed part; the first spindle is opened and the workpiece is released; after that, the second spindle is brought to initial position for part processing, and by means of the cutting tool there performed is processing of outer and inner surfaces of the second threaded element and cutting of the internal conical thread, upon completion of which the ready-made part is released by the second spindle and removed from the machine.

EFFECT: method allows making couplings without any pre-processing of a coupling workpiece along an outer surface and providing the required alignment of both coupling halves.

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