ROCK‐HARD TRIBOLOGY

The author compares the results of a series of tests on BQ wireline and TBW mining bits containing 30/40 US mesh De Beers SDA100 diamond abrasive at 60 concentration when drilling Cornish grey granite at constant penetration rate or constant thrust loads. The results confirmed earlier findings that, by setting the penetration rate of impregnated drill bits, efficient drilling can be maintained throughout the life of the bit.