... Made by professtional geo -equipment and tooling manufacture. Diamond reamer has various dimension for different drilling processes, ... quartzite, hard slate, chert, basalt, etcHot-Pressed Diamond Drill Bit Hardness & Rock Drillability Grade FormRock Drillability ... , 20, 22-25Silty Mudstone, Carbonaceous Mudstone, Siltstone, Medium-Grained Sand Stone, Trhough Amphibolite, Lamprophyre, etc520, 22 ...