As with conventional DTH air hammers, the compressed air powers the Reverse Circulation (RC) hammer and carries the cuttings out of the hole. In RC drilling though, the cuttings are channeled back to the surface through the inner tubes in the RC hammer and, consequently, the drill rod, rotational head and sample hose, which is attached to the top of the “cyclone”, where the cuttings are slowed down, separated from the air and collected in a samples bag. The need for clean, uncontaminated samples led to the development of the RC hammers in the 90’s and the RC drilling technology has been continually improving ever since to address the demand for drilling deeper and in more difficult geological conditions. Thus, Drill King’s XT RC50 hammer was conceived with the goal of creating a simpler design with less internal parts that last longer. The inner sampling tube, which provides continuous sealed pathway for the drill cuttings from the bit face to the surface, was given particular engineering attention as it is a critical component that normally wears prematurely. For this reason, Drill King fine-tuned its steel material selection and heat-treating specifications to produce a sampling tube with wear-resistance properties. Overall, the XT RC50 hammer is easy to disassemble and put back together as it features only 11 internal parts (not counting the o-ring seals). All hammer parts are precisely machined to eliminate air leakage, thus boosting drilling penetration rates and optimizing air consumption. Drill King RC bit sizes from 5-3/8″ to 5-3/4″.