 Speed
The pilot bit is large like a conventional DTH drill bit leaving less area for the wings to have to ream. Less torque is needed because the three wings extend for more reaming coverage.
Stability
Concentric reaming does not create unbalanced lateral forces like eccentric reaming can when reaming only on one side. The concentric under reamer drills better and is more stable in boulders due to the increased reaming coverage.
Flushing
Good flushing increases button life by effeciently removing cuttings while extending the life of the entire system and additional exhaust jets located between the wings reduce build up.
Durability
Increased bit surfaces (pilot and wings) allow more carbides for increased durability. |
