... bit 1.from Zhuzhou city(the tungsten carbide base) 2.100% virgin raw material cemented carbide ... coal cutting picks, oil cone bits and scraping knife bits, used in geological prospecting, coal mining and ... coal cutting picks, oil cone bits and scraping knife bits, used in geological prospecting, coal mining ... display of cemented carbide button bit with K10 type 34mm length for chisel drilling bits used in ...