rock drill button bit feature: 1The taper angle: 4, 5, 6, 7, 11 ... can supply Taper hole Spherical rock drill button bit The models are Off center ball three teeth drill ... four teeth drill bit , Ball five teeth drill bit, Ball six teeth drill bit, Ball seven teeth drill bit The taper angle ... Can be 15~25mm, besides, we can produce drill bit according to your specification requirements. If you have any ...