Designed to endure
demanding environments

Hydraulic rock drills and drifters

DF430X – DF430S – DF430F – DF500X – DF500S – DF530X – DF530SDF538L – DF540L – DF540L-BLT – DF550L – DF550L-2M – DF550L-EXT – DF560L - DF560L-2M – DF560L-EXT


High performance hydraulic rock drill

Doofor DF550L-EXT is a high frequency rock drill equipped with a hydraulic back hammer. The back hammer enables removing stuck drill steels from the rock and opening the threads of lines of drill bars in extension bar drilling.

The DF550L-EXT has a very low overhead, only 84mm from the drill center line. The rotation motor of the DF550L-EXT can be installed on the right hand or the left hand side.

The rock drill has a separated flushing box. Flushing media can be water or air.

Optimal maximum hole diameter for the DF550L-EXT is 76mm [3”].

The rock drill can be equipped with male R32, R38 and T38 shank adapter (striker bar).

Doofor DF550L-EXT hydraulic rock drill
 Technical Data
 Percussion power  17 kW
 Percussion pressure  160 bar
 (oil flow)  (95-120 litres/min)
 Rotation motor*  125 cm3
 Speed max.  250 rpm
 Torque*  796 Nm
 Oil flow max.*  95–120 litres/min
 Gear ratio  65/40
 Lubrication  Air-oil mist, min. 200 g/h
 Flushing air pressure  5–7 bar
 Flushing air flow  4000 litres/min
 Flushing water flow  150 litres/min
 Weight  170 kg

Feed force (pressure) must be adjustable during operation
*) Numbers given are for standard rotation motor (200cm3) at an intermittent pressure of 275bar [3989psi]. Motor options are 80cm³, 100cm³, 125cm³, 160cm³, 200cm³, 250cm³. For professional use only as a component of a hydraulic system.


76 mm
Optimal maximum
hole diameter
17 kW
Power class
Shank size