... of used productFormationsoft and medium formation, hard formationButton bitsmall tooth, big tooth, conical inserts, chisel insertsMaterialalloy steel, carbidePackingwood box, ... , Asia, south AmericaReputation First, Client's Requirement First. How to judge the quality of the used drill bits:1 ... >the quality of the bearingshipment of steel tooth bits : API steel tooth tricone bits 7-7/8HA116 FOR OIL ...