... usWe are a professional productions base of series of rock drilling tools, mining tools, DTH Drill tools. Construction tools and ... H19x108mm, standard hex. Bit diameters include 20-42mm.2. Tapered drilling tools (Tapered Drill Steel)Including:Shank H22x 108mm, (6, 7 ... 11, 12 degree taper).Bit diameter: 28mm-57mm.3. Extension drilling toolsButton bit, face design: Flat face, Drop centre, Normal and ...