R200 Well Expansion Tool ST68.S for Efficient Drilling Applications

New, not used, well reamer, d. 200 mm, thread S?68, shape of pins hemisphere, diameter of guide 102 mm, length 280 mm, weight 21,6 kg, number of pins: frontal 15xØ16mm, peripheral 12xØ16mm, angle of inclination of peripheral pins 35?, flushing holes - 3xØ18 mm. The confirmed resistance in drilling conditions of rocks overlaying the ore body are quartz porphyries, rocks stable, but prone to detachment during the formation of the roof of the chamber, the coefficient of strength on the scale of Professor Protodyakonov f 17.0 -19.0, category XVII.

The underlying rocks are massive irregularly chloritised quartzites. The rocks are stable, the coefficient of strength on the scale of Professor Protodyakonov f = 17.0 - 18.0, category XVII - not less than 27 spourometers. Stability is confirmed by the Act (Protocol) of tests at the mines of mining enterprises, approved by the director of the complex.