... drilling Advantage: 1> TCI tricone bit, steel teeth tricone bit,rock bit,milled tooth bit,tci bit,steel tooth bit2> Certified by ISO9001 ... rubber seal or metal seal8> including drill rods,drill collar,rerun steel tooth bits, ,used drill bits stock,used mud pumps,etc9> ... on bit body, the bit has good gauge protection inserts on bit body, the bit has good gauge protection and up drill capability3> ...