Center Rock Inc. offers one of the most complete lines of downhole drills, and bits ranging from 3.5-inches (89-millimeters) to 144-inches (3,658-millimeters). Designed for all rock drilling applications, including blasthole, exploration, HDD, foundation, water well and underbalanced gas. Our hammers provide optimal performance in wet or dry conditions, and our bits provide the best value with a full range of face and head designs, button insert configurations and shank styles suited to any geology.