A drum cutter is driven directly by the excavator's hydraulic system. High-pressure oil flows from the excavator's pump to the hydraulic motor inside the cutter, generating strong torque to rotate the drums.

During operation, the rotating drum is pressed against the working surface. The picks engage the material at an efficient cutting angle—typically between 15° and 30°. Thanks to their wedge-shaped geometry, the picks penetrate the material under the combined force of rotation and pressure.

The cutting process varies by material type:

Soft rock and soil (shearing mechanism)

Picks peel material away in a continuous shearing motion, similar to a planer removing layers.

Hard rock and reinforced concrete (fracture mechanism)

The rotating drum generates high-frequency micro-impacts and compressive stress. These stresses create cracks that propagate until the rock breaks apart.