... ,7,11,12 degree taper) taper rods in most lengths.button bits, cross type bits and chisel bits with(6,7 ... :28mm-57mm.3. Extension drilling toolsButton bit, face design: Flat face, drop centre, Normal and retrac body.tungsten carbide(Buttons):Spherical, ballistic and ... all kinds of round cutter bit and flat cutter bits for excavate coal machine as the replacements of kennametal. Such as U76 ...