T45 Threaded Button Bit is the most important size for benching and long-hole drilling underground,Premium designs and steel and premium tungsten carbide insert grade T6 supplied by Boart Long year, Offers industry-leading strength and penetration rates for more productivity，Excellent straightness and hole clean quality, Get et max.drilling per performance for rock drill with long life to save up fuel cost st rate. Used in bench drilling, underground long-hole drilling to match