... certified by ISO9001&API 2))used for water well, oil field 3)IADC:114-117,127,437,517,617,637 TCI ... rate3)Strong cutting structure durability4)be used for water well, oil field, underground, construction, geothermal, directional boring5)Be used to ... TypeTricone bits,Steel tooth bits,PDC bits Appliable water well, oil field, construction, geothermal, directional boring, and underground foundation work ...