DTH drilling machine is a kind of drilling machine mainly for drilling rocks. The machine can widely be used in large diameter hole drilling operations of small and medium-sized mines, road construction, water conservancy and rock excavation, as well as drilling bolt holes in slope support, tunnel support and foundation pit support. Two Types 1. Diamond Core Drill Machine, Drill Machine Core Bit, Core Drill Rig Machine manufacturer / supplier in China, offering Gold Mining Drilling Rig Hard Rock Drilling Rig Mining Drilling Machine Core Drill Rig Machine Special, Hydraulic Mini Dumper/ Mini Dumper Small Tracked Crawler Dumper, Diesel Engine Hydraulic Mini Dumper/ Mini Dumper Small Tracked Carrier The C620H Jack-less blast hole drill is designed to drills holes ranging from diameter of 4-1/2 inch (114.3mm) to 6-1/2 inch (165.1mm) to a maximum depth of 118 ft (36m). The C620H is a built for high efficiency and productivity to drill in medium to hard Limestone, Dolomite quarries and Aggregate mines. View More.