Hydraulic systems transmit power through pressurised liquid; pneumatic systems use compressed gas. Liquids are far less compressible, so hydraulics can produce high force with controlled motion. Pneumatics favour fast, simple movement where moderate force and some compliance are acceptable.
Force and control
Hydraulic cylinders deliver high force from compact actuators and can hold controlled loads when the circuit is designed correctly. Pneumatic cylinders move quickly but air compressibility makes precise low-speed motion and rigid positioning more difficult.
Energy and environment
Compressed air is convenient but energy-intensive when leaks, pressure drops and compressor losses are included. Hydraulic leaks create housekeeping and contamination concerns, while oil temperature and cleanliness directly affect reliability.
Choose around the task
Define force, speed, stroke, cycle rate, positioning, duty and safe failure behaviour. Then compare the complete power unit, valves, conditioning equipment, piping, controls and maintenance capability rather than only the actuator.