Key Takeaways:
Both use a pressurized film, but liquid and gas media differ sharply. Compare cleanliness, speed, load, stiffness, and the 'air-hammer' instability risk to choose correctly.
Two Films, One Idea
Both hydrostatic (liquid) and aerostatic (gas) supports levitate a part on a pressurized film instead of mechanical contact. The medium changes everything.

Liquid Hydrostatic
Uses hydraulic oil. Strong load capacity and stiffness, excellent damping, tolerant of moderate contamination. Best for heavy, precise, vibration-sensitive work.
Gas (Aerostatic)
Uses compressed air. Extremely clean (ideal for semiconductor/optical), minimal temperature rise, and capable of very high speeds. But load capacity and stiffness are lower, and it carries an 'air-hammer' (pneumatic resonance) instability risk under certain conditions.
Decision Guide
- Choose aerostatic for ultra-clean, high-speed, light-load, low-heat applications (lithography, metrology).
- Choose hydrostatic for high load, high stiffness, heavy cutting, and damping (grinding, turn-mill, rotary tables).
Bottom Line
When precision must survive heavy cutting forces, liquid hydrostatic support is the safer, stiffer choice.