For over forty years, Numa has built a strong legacy of high quality, Made in the USA rock drilling hammers, bits, and accessories for drilling DTH, HDD, and reverse circulation holes 3½ to 50½ inches (89 – 1283 mm) in diameter. Our long history of innovation and expertise has resulted in a wide range of reliable DTH and HDD products perfectly suited for hard rock, overburden, or loose strata formations. Numa provides some of the industry’s top rock drilling experts providing a wide array of insight on drilling methods, tooling, fluids, bits, reamers, rock tools, swivels, and more.