A down-the-hole drill, usually called DTH by most professionals, is basically a screwed on the bottom of a . The fast hammer action breaks hard rock into small cuttings and dust that are evacuated by a fluid (air, water or ). The DTH hammer is one of the fastest ways to drill hard rock. The system is thought to have been invented independently by Stenuic. [pdf]
There are drill charts and velocity calculators one can refer to online, but the recommended uphole velocity is about 3000 feet per minute. “Depending on what size drill pipe, what size borehole, what tha. [pdf]
Enter your inquiry details, We will reply you in 24 hours.