Evaluation of drilling efficiency by percussion testing of a drill bit with new button arrangement

Rock drilling machines are commonly used for surface drilling, soil nailing reinforcement, tunnel excavation, and underground mining. These machines use drill bits that directly impact into the rock and are operated by percussive force and torque. Drill-bit buttons need to be designed to increase drilling efficiency; here, we present the results of a series of single blow tests on granitic rock samples using a piston drop type percussion testing system that enable us to compare the drilling efficiency of a new button arrangement design with conventional arrangements. Drilled rock volumes were measured by laser scanner after testing, and drilling efficiencies were evaluated by calculating percussive energies and drilled volumes. The results indicate that the new button arrangement design can be used to improve the drilling efficiency.