A down-the-hole hammer is the part that actually breaks the rock. The bit is mounted directly on the hammer, the piston strikes the bit from behind, and compressed air carries the cuttings out of the hole. Because the impact happens at the bottom of the hole rather than at the top, energy is not lost through the drill string as depth increases — which is why DTH drilling holds its penetration rate in hard rock at depth.

Typical applications

Quarry and open-pit blastholes — Production holes where penetration rate and hole straightness both matter.
Water well drilling — Bedrock sections below the casing, particularly in hard abrasive formations.
Geothermal and monitoring boreholes — Holes that must stay straight and clean for the full depth.
Foundation and anchor holes in rock — Short holes in hard rock where a top hammer would deviate.
Micro-piles and ground improvement — Repeated small-diameter holes in difficult ground.

How it works

The hammer contains a piston that reciprocates under air pressure and strikes the top of the bit shank. A foot valve controls the air so that the piston is driven down on the power stroke and returned on the up stroke, while a portion of the air continuously by-passes to flush cuttings past the bit and up the annulus. The shank and the bit must match exactly — a mismatched shank is the most common cause of premature failure.

Working pressure range in the table must be met at the hammer, not at the compressor outlet — allow for hose and coupling losses.
Air consumption rises with pressure; under-supplying air drops the strike rate sharply.
The bit shank designation must match the hammer shank, and the bit head diameter must match the hole diameter range.

How to specify the right model

Pick the hammer from the hole diameter and the air package you have, in that order. A hammer that is too large for the compressor will drill slower than a smaller one correctly supplied.

Read the hole range for the model and stay inside it — both the bit and the hammer are designed around that band.
Check working pressure and air consumption together against your compressor free air delivery at the working altitude.
Confirm the connection thread matches your drill string; adapters cost money and add a failure point.
For deep holes, weigh the weight and length of the hammer: they affect string handling and hole deviation.

Frequently Asked Questions

How do I know which shank type I need?

The shank type is determined by the hammer family you are already using, or by the bit you intend to run. SP, QL, SD, BR and CIR are different shank standards and are not interchangeable. Tell us your existing hammer or bit and we will confirm the match.

Can I use a larger bit on the same hammer?

Within the hole range listed for the model, yes. Beyond it the piston-to-bit energy transfer and the flushing air balance change, and performance drops.

What air pressure do these hammers need?

Each model lists its working pressure range. The compressor must deliver that pressure at the hammer with the specified air consumption; most field problems come from pressure measured at the compressor rather than at the hammer.

Do you supply matched bits?

Yes, bits in the matching shank and head diameter are supplied with the hammers, so the pair is known to fit.

How do I choose between the 42 models in this range?

Start with the hole diameter and depth you need, then check the transport and site dimensions against the specification table. Every model in this range has its own detail page with the full datasheet; if two models look close, send us the job details and we will tell you which one we would quote.

Tell Us About Your Site

Send us your geology, hole diameter and target depth.

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