A classic question
"Should my equipment use grease or oil?" This is the most common lubrication selection confusion. It is not about which is better, but which fits better.
Four-way comparison
| Dimension | Grease | Oil |
|---|---|---|
| Sealing / dust | Good (self-sealing) | Poor (needs extra sealing) |
| Cooling | Poor | Good (circulates heat away) |
| Suitable speed | Medium-low | Medium-high |
| Maintenance | Less (long life) | Regular oil changes |
| Application | One-time fill | Continuous supply / circulation |
When to use grease
- Sealed bearings, hard-to-reach lubrication points;
- Medium-low speed, heavy load, intermittent operation;
- Needs dust, water and leakage protection;
- Long-term maintenance-free scenarios.
When to use oil
- High-speed operation requiring cooling (e.g. spindles, gearboxes);
- Needs circulating filtration to carry away wear debris;
- Centralized oil supply systems;
- High temperature where grease would bleed away.
Conclusion
Low speed, sealed, maintenance-free → grease; high speed, cooling, circulation → oil. Many machines combine "grease-lubricated bearings + oil-lubricated gearboxes". When unsure, provide speed, temperature and sealing conditions for engineering judgment.