... ,437,517,547,617,637Applicable forPetroleum & gas, water well and mining Bearingmetal bearing(HJ), rubber bearing(HA)Advantagehigh quality with ... reasonable price because of used productFormationsoft and medium formation, hard formationButton bitsmall tooth, big tooth, conical ... of steel tooth bits : API steel tooth tricone bits 7-7/8HA116 FOR OIL AND WATER WELL DRILLING