JINKE JK 930 high pressure DTH drilling rig. For the hard stuff, where a low pressure air package stalls the hammer and one hole eats half a shift. The JK 930 HP runs 2.4 MPa at the hammer and 110-165 mm bits, which is the point where granite and hard basalt start cutting at a sensible rate. For hard rock benches 2.4 MPa at the hammer. High pressure air keeps the piston hitting hard at depth, so penetration does not fall off as the hole goes down. 5 and 6 inch high pressure
