... specializes in manufacturing:Tricone bits,steel tooth bit,milled tooth , rock roller bit,tricone bit,tungsten carbide insert rock bit, ... tri-cone drill bit ,3 cone bits,rotary bit, TCI tricone bit ... a call) .Recommended drilling parameters of tri-cone rock bits Rock formationBit typeBit sizeDrilling weightRotary speedmminchkN/mmr/minVery softSoft ...