Rock drilling tools Tapered Drill Rod is to provide 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 drill bit end. Tapered steel lengths are measured from the collar to the bit end. Holes are usually drilled in 0.6 m increments to accommodate the air leg feed length. The drilled steel is extracted and followed with a slightly smaller diameter rock drill bit on the next steel length in the sequence.

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 Y6, Y10, Y24, YT24, YT27,YT28,YT29A pneumatic or other hydraulic rock drills . For low impact rock drills and softer rock formations, a narrow tape range of 7 degrees is used, such as Indian, 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.