3. Extension drilling tools Button bit, face design: Flat face, Drop centre, Normal and Retrac body. Tungsten carbide (Buttons): Spherical, Ballistic and Conical. (Threaded R32, R38, T38, T45, T51 ; bit diameter: 45mm-127mm); Couplings sleeves- manufactured with a middle stop to prevent walking along the thread. Include couplings sleeve (threaded R22, R25, R28, R32, R38, T38, T45, T51) Shank adaptors - carburized and manufactured with tight tolerances and controlled straightness. |