Patriot 50 and Patriot 80 down-hole hammers provide fast penetration rates for horizontal and vertical rock-drilling projects. The Patriot 50 and Patriot 80 drill holes from 5½ to 6 1/8 inches in diameter and 7 7/8 to 10 inches in diameter, respectively. The feed-tube assembly is attached directly to the back head of the hammer, which allows alignment of all hammer parts. The units can handle back pressure drilling conditions, as well.