... improved with new formulas and new techniques for insert bit.2)Multiple gauge protection with gauge trimmers on ... bits, drill pipe, Mud pump and stabilizers for water well, oil field, construction, geothermal, directional boring, and ... of new and used(rebuilt) drill bits used for oil filed, waterwell. Including tricone bits, PDC bits ... pdc bits API Kingdream 8 1/2''TCI Tricone Bit for oil drilling