Tapered drill rod (taper steel rod, taper drill steel), which provides a hexagonal chuck section to provide leverage for the rotation chuck bushing. It usually has a forged collar to maintain the proper shank striking face position in the rock drill, and a tapered bit end. For drilling medium-hard to hard and abrasive rock formations, 11 and 12 taper degree rod are widely used on heavy-duty modern hydraulic drill rigs. While, 6 and 7 taper degree rod are applied for light-duty rock drill, such as the hand held pneumatic rock drill Y18, Y20, Y24, Y26, YT24 and YT28. KAT drilling tools CO.,LTD. offers a complete line of tapered rods and bits for all of your hand-held pneumatic drilling needs. For mine, quarry and tunnel work, we provide quality tools that withstand the toughest rock drilling demands. With our comprehensive product line, you can find the exact configuration to integrate into your drilling operation. Our tapered bit and rods come in a variety of taper angles, and we provide tapered rods in a full range of shank configurations and steel hex diameters. Our tapered bits include both cross and button designs, as well as chisel design. SANSUNG tapered rods are available with high-frequency or fully carburized heat treatments. Taper button bits 1.taper degree: 4°46″, 6°, 7°, 11° and 12° 2.diameter: 28mm to 45mm 3.socket inside diameter: 19mm / 22mm / 25mm 4.length: 50mm to 80mm