Center Rock Inc. offers one of the most complete lines of downhole drills and bits, ranging from 3.5 inches (89 mm) to 144 inches (3,658 mm) 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 drill in any geology.