... with a middle stop to prevent walking along the thread. Include couplings sleeve (threaded R22, R25, R28, R32, R38, T38, T45, T51)Shank ... model etc.5. Excavate coal cutter bitsInclude all kinds of round cutter bit and flat cutter bits for excavate coal machine ... . (Rod, Cross bits, button bits and X-type bits etc). Round Shank Cutter Bits