Designed to endure
demanding enviroments




High performance hydraulic rock drill

Doofor DF550L-EXT-2M is a high frequency rock drill equipped with a hydraulic back hammer and two OMS-series rotation motors. The back hammer enables removing stuck drill steels from the rock and opening the threads of lines of drill bars in extension bar drilling. Two motors are optimal in broken or fissured rock conditions or when drilling mixed materials, such as soil or moraine.

The DF550L-EXT-2M has a low overhead of 84mm from the drill center line. The rock drill has a separated flushing box. Flushing media can be water or air.

Flushing head can be turned upside down. Motor fittings direction can be specified (up, down or side). Accumulator valve direction can be specified. The rock drill is equipped with two OMS-series rotation motors. This enables continuous, high torque (1592Nm) while still maintaining a high rotation speed.

Optimal maximum hole diameter for the DF550L-EXT-2M is 76mm.

Technical Data
Percussion power 17 kW
Percussion pressure 160 bar
(oil flow) (95-120 litres/min)
Rotation motors 80-200 cm3
Speed max. 250 rpm
Torque (2*125 cm3) 1592 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

76 mm

Optimal maximum
hole diameter

17 kW

Power class

R32, R38

Shank size



Feed force (pressure) must be adjustable during operation
*) For professional use only as a component of a hydraulic system.

Feed force (pressure) must be adjustable during operation. Rotation torque and oil flow values given are for a typical rotation motor. See full brochure for detailed information on different rotation motors. Percussion pressure mentioned is a recommended value for a typical application. The product is intended for professional use by skilled personnel. Doofor reserves all rights for changes without prior notice.

©2019 Doofor Inc