... , H19x108mm, standard hex. Bit diameters include 20-42mm.2. Tapered drilling tools (Tapered Drill Steel)Including:Shank H22x 108mm, (6, 7, 11 ... , 11, 12 degree taper).Bit diameter: 28mm-57mm.3. Extension drilling toolsButton bit, face design: Flat face, Drop centre, Normal and ... straightness.4. DTH hammers and DTH bits (Down The Hole Drilling)Offer IR hammer, DHD3.5, DHD340a, DHD360, DHD380, and low ...