The 390 Series Tools are configured for Ultra Deep Hard Rock Coring. The Drill String in a mixed string of Hydril Wedge Lock Oil Field Tubing for the upper segments and Mining Coring HQ Style Core Rods for the Lower Segment. This arrangement enables high speed coring in excess of 12,000 feet. The 390 Series Inner Tube is smaller in diameter than HQ to allow passage through the reduced ID Hydril Tubing.
