... tools and excavating coal pick cutter tools.1. Integral drill steels (Integral Drill Rods)Shank H22x108mm, H19x108mm, standard hex, Bit diameters ... include 20-42mm.2. Tapered drilling tools (Tapered Drill Steel)Including:Drill rods with Shank H22x108mm,(6,7,11,12 ... 3. Extension drilling toolsButton bit, face design: Flat face, drop centre, Normal and retrac body.tungsten carbide(Buttons):Spherical, ...