These drill bits are specifically engineered to enhance cutting power and debris removal, ideal for drilling through harder rock types like sandstone and limestone. Their triangular shape concentrates the cutting force, effectively penetrating tough layers.
[pdf] DTH technique was used in well drilling exclusively to dig, accurate, vertical bores, and rotary drilling was used to turn the hole. The Directional DTH system, patented by Atlas Copco, was first used successf.
[pdf] The IADC Drilling Manual has recently been updated and is now available in its 13th edition in the IADC Bookstore. This book is the definitive manual for drilling operations, training, maintenance and troubleshooting.
[pdf] 
