GALLING RESISTANT DRILL PIPE TOOL JOINT AND CORRESPONDING DRILL PIPE

摘要

A drill pipe tool joint comprising:a pin including a male threaded portion at an outer surface; and a box including a female threaded portion at an inner surface the female threaded portion to be screwed and fastened to the male threaded portion in a contacting zone consisting of a male threaded contacting surface and a female threaded contacting surface wherein at least a portion of the male threaded contacting surface or a portion of the female threaded contacting surface is a surface layer consisting of a hard metal and respectively at least a portion of the female threaded contacting surface or a portion of the male threaded contacting surface is a surface layer consisting of a soft material and where said both surface portions are contacting surfaces after screwing.