AbstractsEarth & Environmental Science

"This paper describes a comparative study which was made of the wear and efficiency of different types of rock-drill bits when used under various drilling conditions...The four types of experiments which were carried out had the following purposes: 1. Determine the influence of the size of the bit. 2. Determine the influence of the design of the bit. 3. Determine the influence of the type of hammer. 4. Compare the performances of steel and tungsten carbide bits in limestone and in granite" – Introduction, p. 1.