TDD,born for drilling. 

TDD group have been focusing on DTH drilling for 16 years. We are specialized in manufacturing various DTH drilling hammers、matched drilling bits、drilling rigs and drilling pipes for water wells、mines and oil industries.

TDD has been promoting productivity in drilling industry, SPM ensure the safety and stability of drilling engineering, and provide professional, efficient and reliable whole drilling solutions. 

TDD have made tremendous development at the basic of high-quality, low price, good service since its establishment. All friends both at home and abroad are warmly welcomed to come here to establish and develop business relationship with us. 

Principle and structure: the drilling tool is based on the middle ladder of the head, and the pipe boot ladder of the steel pipe to transfer the impact force to the steel pipe. In front of the punch head is a triangular inner splice keyway, which drives a positioning hole bit with a triangular concentric shaft which can slide back and forth. Between the punch head and the opening bit, there is a fan-moving reaming drill piece in each of the three oblique circular arc grooves on the end face of the punch. When the front opening bit touches the ground and retreats backward, the head of the opening bit changes the diameter of the triangular shaft at the bottom of the inclined surface. The reaming sheet opens outward into a reaming hole. When it is necessary to withdraw the drilling tool, the reaming piece is extruded by the pipe boot, and the reaming bit is pushed open and the drill is contracted inward, so that the whole drill tool is reduced and recovered.