Development and application of integral spiral drill pipe

when welded spiral drill pipes coorperate air pressure rig to drill a soft coal seam, the spiral ribs are easy to crack, desolder and not wear resistant, resulting in difficulty in borehole formation even scraped borehole. Spiral grooves are machined in the thick wall of pipes through mill cut, the joint is improved, surface treatment of the thread is made, finally the integral spiral drill pipe is developed. The paper introduced briefly the designa nd the process flow of the integral spiral drill pipe. The test results in Panyi Mine, Huainan, showed that the integral spiral drill pipe has good general mechanical properties, powerful hole-forming ability, long service life, can not only replace welded spiral drill pipe to drill soft coal seam with air pressure, but also replace conventional flat drill pipe to drill rocks.