Rock Drilling Tools

Raiseboring Tools

Pilot bits, stabilisers, drill rods, reaming heads and cutters for raiseboring ventilation shafts, ore passes and access raises.

Features

  • A raise is drilled in two stages: a pilot hole down to the lower level, then a reaming head pulled back up through it.
  • Cutter selection follows rock strength and abrasiveness, and cutters are inspected at every rod change because a failed cutter damages the head saddle.
  • Pilot hole deviation decides whether the reaming head can be coupled at all, so stabilisers are part of the string rather than an option.
  • Reaming head diameter is built up from a base head with cutter rings, which lets one head serve more than one raise diameter.
  • Rod handling and thread cleanliness matter: the string is in tension while reaming, and a damaged thread means a dropped head.

Specifications

Figure Typical range Unit Why it matters
Pilot hole diameter 229 - 349 mm Matched to rod and reaming head.
Raise diameter 700 - 3 000 mm Head size and cutter count.
Cutter type carbide insert / milled tooth Rock strength and abrasiveness.