Abstract: A method is provided for maintaining threaded joints of a tool string to prevent jamming of the threads by rotation of a tool string required during movement of the tool string through a generally horizontal production portion and a curved bore portion of the well. Each thread joint is formed by use of an externally threaded pin and box configuration with the external diameter of the box substantially exceeding the external diameter of the pin. The cooperating threads are configured so that limited relative axial movement produces locking of cooperating threads against realtive rotation after full engagement. Relative axial movement is produced during makeup of the tool string by rotating a sleeve threadably mounted on the exterior of the pin and engagable to produce axial movement. The sleeve has an external diameter less than the box to prevent frictional engagement of the sleeve with the bore wall of the curved bore portion of the well.

Abstract: A method is provided for applying grooved bands of hardsurfacing on a tool joint for earth boring drill pipe. The hardfacing of the tool joint has tungsten carbide granules in an alloy steel matrix. The tool joint is rotated and an arc between an electrode and the tool joint is provided to create a weld puddle. The electrode is reciprocated parallel to the tool joint axis and the granules are fed into the weld puddle with the puddle being applied to the grooved bands around the exterior of the tool joint to a groove depth of from between about 0.75 inches to about 0.150 inches. The feed of the granules into the weld puddle is discontinued and the weld puddle is continued to be applied around the tool joint and in the grooved bands to provide a protruding substantially tungsten carbide free hardfacing surface about the outer diameter of the tool joint of from between about 0.050 inches to about 0.175 inches, and the hardfacing surface is machined down to substantially the outer diameter of the tool joint.