Tapered drill rod, also called taper rod, tapered drill steels, it 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. Tapered steel lengths— available from 0.6 m to 3.6 m in length—are measured from the collar to the bit end. Shank Hexagon: 19 x108 mm, 22x 108mm, 25 x108 mm, 25 mmX159 mm 6, 7, 11, 12 degree taper in most lengths, taper degree of drill steel is mostly imports for excellent drilling productivity. For drilling medium-hard to hard and abrasive rock formations, taper angles of 11 and 12-degrees are normally used on modern drill rigs, like crawler hydraulic rock drill. Also for Y6, Y10, Y24, YT24, Mobile rock drill pneumatic and hydraulic. For low impact rock drills and softer rock formations, a narrow tape range of 7 degrees is used, such as India, Saudi’s granite and marble quarry. A comprehensive range of taper button bits, cross bits and chisel bits with 6, 7, 11, 12 degree taper, drill hole diameter: 28mm-57mm.