Atlas Copco Cobra Combi — The Gas Powered Rock Drill
One 55-lb machine, one 185cc two-stroke engine, zero compressor: the Cobra Combi drills 8–12 inches per minute in solid granite to 6.5 feet deep, then flips a lever and breaks like a 55-lb jackhammer. It is the rock drill you carry to places air hoses cannot go.
The short version
If you need to drill rock away from a compressor — fence posts in ledge, anchor holes, plug-and-feather splitting, blast pilot holes — the Cobra Combi is the tool, and it breaks concrete too. If you only break, the Cobra PROe hits three times harder per blow. Have compressor air? The pneumatic rock drills drill faster for production work, and every rock drill we stock is at the all-brands rock drills category.
The Machine
One product, two tools — and everything it needs below.
Cobra Combi Gas Rock Drill & Breaker
The unique switching mechanism moves between rotary percussive drilling and straight breaking in seconds. Magnapull starting fires the 185cc engine in any weather, the 2.7 hp head spins 7/8 in. hex steel at 250 RPM under 2,700 BPM, and the whole rig runs about a third of a gallon of premix an hour. Our best-selling gas machine, and the classic one-man answer to rock since the Pionjar days.
Choose it when: the job is holes in rock — and sometimes breaking — anywhere a compressor is not.
Key specs
Complete the Kit
Cobra Combi Questions
How fast does the Cobra Combi actually drill?
Atlas Copco rates it at 8 to 12 inches per minute in solid granite with a 1-1/3 in. bit — softer rock and smaller bits go faster. Maximum practical depth is about 6.5 feet using extension steels.
Is the Cobra Combi a replacement for the old Pionjar or Cobra mk1?
Yes — the Combi is the current descendant of the Pionjar 120 and Cobra mk1/148 line that generations of crews ran. Same concept, same one-man gas drill-and-break role, with a modern engine, Magnapull starting, and much better vibration numbers. Steels interchange where shank size matches (7/8 x 4-1/4 hex).
Can it break concrete as well as drill?
Yes — flip the selector and it becomes a 55-lb breaker at 15–18 ft-lb per blow. For breaking-only work the Cobra PROe hits 44 ft-lb, but no other machine in the family drills.
What fuel does it use?
Regular 90–100 octane gasoline mixed 2% (50:1) with two-stroke oil — we stock the factory synthetic. The 0.32-gallon tank runs roughly an hour of steady work.
Gas or pneumatic rock drill — which should I buy?
Gas if the job moves and the compressor cannot follow: remote sites, scattered holes, emergency work. Pneumatic if you drill at volume near air — a BBD or SRD on a compressor drills faster all day and costs less per machine. Many crews run one Combi for reach and pneumatics for production.
What bits and steel does it take?
Standard 7/8 x 4-1/4 in. hex shank drill steels with carbide cross or button bits — the same steel family as our pneumatic drills, stocked in lengths to its full 6.5 ft reach, plus extension steels and couplings.
Is it loud? Can one person really run it?
It is a gas engine and a rock drill — hearing protection always. But it is genuinely a one-person system: 55 lb, carried like heavy luggage, started with one pull, no other equipment on site.
How fast does it ship?
In stock, ships same day on orders by 4 PM Eastern by flat-rate Freight, with steel and oil in the same shipment. Service kits, air filters, and starters are stocked for the Cobra family.
Drill Rock Anywhere You Can Walk
Tell us the rock and the hole and we will set you up with the Combi, the right steels, and the oil to run it.