A DTH (down-the-hole) drilling rig puts a pneumatic hammer at the bottom of the drill string, so the bit strikes the rock directly while the string rotates. That makes it a strong choice for hard rock. Before you buy one, work through these questions.
1. How deep and how wide do you drill?
List the depth you drill most often and the deepest hole you expect, plus the hole diameters you need. Rigs are built for a range of depths and diameters, and buying for a job you rarely do adds cost.
2. What is the ground like?
Hard rock, mixed ground with boulders and soft formations all behave differently. DTH works best in hard and medium-hard rock. If your work is mostly soft ground, ask whether another method suits you better.
3. Which carrier suits your sites?
- Truck mounted: quick to move between distant sites, common for borewell contractors.
- Crawler mounted: copes with rough, uneven or steep ground, common in quarries and mines.
- Tractor mounted: lower cost, suited to farm work and smaller contractors.
4. What compressor will you run?
A DTH hammer runs on compressed air, so the compressor has to match the hammer and the depth. Ask the rig maker to help you match them.
5. Plan for service and spares
A rig earns money only while it is working. Choose a maker who can supply spares and repair hydraulics close to where you work, and ask what they stock.
Tell us your requirement
Send us your depth, hole diameter, ground type, carrier preference and location, and we will suggest a rig that fits the work.
