Carbide Tips for coal drill bits: Grade: YC6 YC8, YC8C YK05 Complete Specifications Stable ... ≥2150For coring crowns, electronic coal drill bits, coal cutting picks, oil cone bits and scraping knife bits, applied in geological prospecting, coal ... 5 ≥2320For coring crowns, electric coal drill bits, coal cutting picks, cone drill bits and scraping knife bits, used in geological prospecting, coal mining ...