... Bit size:56-153mm(3,4,5,6in Well drilling equipment parts-PDC bitZhengzhou LD Diamond products as professional ... hardness, abrasion resistance and impact resistance, are widely used for oil/gas well drill bit, geological drill and ... mining drill bit, also could be used for diamond tools for cutting , grinding, polishing. Size13041306130813131608161316161908191319161919Diameter13 ...