Mitsubishi Materials Corp.'s SUPER MAXBIT achieves a stable and balanced drilling system for formations such as gravel, clay, sand mixture, boulders and easy collapsing overburden. It consists of two to three bit wings connected to the DTH hammer. The bit wings are extendable/retractable when the drill string rotates in the forward/reverse directions. It is possible to drill and case simultaneously with the use of a casing shoe. The SUPER MAXBIT also features high-speed and straight hole drilling as well as uniform rotation while drilling boulders, sand and gravel. Mitsubishi Materials Corp.