Made with high quality of raw material through special heat treatment, widely applied in Hand Hole(short-hole) drilling system for dimensional stone quarrying.Tapered button drill bits are widely used for drilling hard or very hard work. They are mainly equipped on rock drilling equipment, well drilling equipment and oilfield equipment.At now, we are exporting the huge quantity of 30mm-42mm for South Africa Platinum mine, Nepal and Chile quarry. Details: Min. Order Quantity: 10 Pieces Supply Ability: 60000Pieces Button shape: Spherical, Ballistic Skirt: Long skirt, Short Skirt. Taper degree: 4°, 6°, 7°, 11°, 12° Package: In wooden case or in carton Shank Hex. Size: 19mm, 22mm, 25mm Application They are widely used in quarrying, mining, road building, railways, highways, water well, hydroelectric power and other basic energy & civil construction projects.