steel tooth bits

Model115,117,121,227,417,437,517,547,617,637Applicable forPetroleum & gas, water well and miningBearingmetal bearing(HJ), rubber bearing(HA)Advantagehigh quality with reasonable price because of used productFormationsoft and medium formation, hard formationButton bitsmall tooth, big tooth, conical inserts, chisel insertsMaterialalloy steel, carbidePackingwood box, steel boxPaymentL/C,T/TDeliveryby ship or plane within 30 daysMain marketMiddle East, Africa, Europe, Asia, south America Reputation First, Client's Requirement First. How to judge the quality of the used drill bits:1>the abrasion of the button bits2>the quality of the bearing