Table 2: Drill rig performances Model Hole diameter Drill-string Secoroc bit type ROC D5 76mm T45 flat front spherical ROC D7 89mm T45 & T51 flat front spherical ROC F7 89-102mm T51 flat front spherical ROC L6 112 & 115mm COP 45 concave front 280m/day ROC 742 76 & 89mm T45 flat front spherical