China 30mm/32mm/36mm/38mm/40mm/42mm/45mm/48mm Tungsten Carbide Tapered Button/Rock/Drill Bit for Air/Rock Drill Machine, Find details about China Tapered Button Bit, Button Bit from 30mm/32mm/36mm/38mm/40mm/42mm/45mm/48mm Tungsten Carbide Tapered Button/Rock/Drill Bit for Air/Rock Drill Machine