... applicationRecommend Grade of Tungsten carbide mining inserts for coal mining tools of Type M23: GradeDensityT.R.SHardnessPerformance & application recommended(g/cm ... , electric coal drill bits, coal cutting picks, oil cone bits and scraping knife bits, usd in geological prospecting, ... crowns, electric coal drill bits, coal cutting picks, cone drill bits and scraping knife bits, used in geological ...