N/a manufacturer / supplier in China, offering Durable Tricone Drill Bit, Tungsten Carbide Inserted for Oilfield or Minining, Tricone Drill Bit and Drill Pipe Connector 12 1/4" TCI Bits for Water Well Drilling, 6 1/4" Miningwell Tricone Carbide Bits Three Cone Trico for Well Drilling and so on.