drill bit,drill bits,rock drilling tools,rock drilling tool,Button bits ... 36mm, 40mm, 42mm, 44mm and so on with different degree taper) Thread Button Bits (33mm, 35mm, 45mm to 89mm, 102mm ... etc4 Tapered Drill RodShank h22x108mm, (6, 7, 11, 12 degree taper) , Length can be according to customers requests. 5 Thread Drill ... and manufactured with tight tolerances and controlled straightness. Drill bit