... Tricone Rock Bit/Well Drilling Bit Hejian Yinhai Rock Bits Manufacture Co.,Ltd is located in Junziguan Industrial District,Hejian city ... the exploitation off natural gas,crude oil ,water well ,geological and underground foundation work all over the ... soft,hard,medium hard,very hard formationApplicationpetroleum&gas ,water well ,mining and tectonic industries ,oil field, construction, geothermal ...