Difference Between 220 and 320 Gear Oil

Technical Comparison of Gear Oil 220 vs. Gear Oil 320

Selecting the appropriate gear oil is critical for the optimal performance and longevity of mechanical systems. Gear oils 220 and 320 are both widely used in various industrial applications, but their differing properties make them suitable for specific conditions. This article provides a detailed technical comparison of these two gear oils to aid in making an informed decision for engineering applications.
 

Viscosity and Viscosity Index

Gear Oil 220

• ISO VG: 220

• Viscosity Index: 102

• Oil Viscosity @ 40°C (cSt): 220.3

Gear Oil 320

• ISO VG: 320

• Viscosity Index: 102

• Oil Viscosity @ 40°C (cSt): 319.4

The ISO VG (Viscosity Grade) number indicates the oil's kinematic viscosity at 40°C. Gear oil 220 has a viscosity of 220.3 cSt, making it less viscous than gear oil 320, which has a viscosity of 319.4 cSt. The viscosity index of 102 for both oils indicates their relative resistance to viscosity changes with temperature.

Pour Point

Gear Oil 220

• Pour Point (°C): -18

Gear Oil 320

• Pour Point (°C): -16

The pour point is a critical parameter for determining the oil's usability in low-temperature environments. Gear oil 220 has a pour point of -18°C, allowing it to remain fluid at slightly lower temperatures compared to gear oil 320, which has a pour point of -16°C. This makes gear oil 220 more suitable for colder operating conditions.

Flash Point

Gear Oil 220

• Flash Point (°C): 242

Gear Oil 320

• Flash Point (°C): 248

The flash point indicates the temperature at which the oil produces vapors that can ignite. Gear oil 320 has a higher flash point of 248°C, compared to 242°C for gear oil 220. This higher flash point suggests that gear oil 320 can better withstand higher operating temperatures, providing enhanced safety and performance in high-temperature applications.

Corrosion and Wear Protection

Both Gear Oils

• Corrosion Test: PASS

• FZG Test (IP 334): >12

Both gear oils pass the corrosion test, indicating their ability to protect metal surfaces from corrosion. Additionally, both oils have an FZG (Forschungsstelle für Zahnrader und Getriebebau) test result greater than 12, signifying excellent load-carrying capacity and wear protection. The FZG test assesses the lubricant's ability to protect against gear tooth surface damage under varying loads.

Application Suitability

Gear Oil 220

• Applications: Suitable for gear systems operating under moderate loads and speeds. Ideal for environments where low-temperature fluidity is essential. Commonly used in industrial gearboxes in colder climates.

• Product Link: Gear Oil 220

Gear Oil 320

• Applications: Designed for heavy-duty applications with higher loads and slower speeds. Suitable for high-temperature environments. Commonly used in industrial gear systems requiring robust protection and high-temperature performance.

• Product Link: Gear Oil 320

Conclusion

In engineering applications, the choice between gear oil 220 and 320 hinges on the specific operational requirements of the machinery. Gear oil 220, with its lower viscosity and better low-temperature performance, is preferred for moderate conditions and colder environments. Conversely, gear oil 320, with its higher viscosity and superior high-temperature resistance, is ideal for heavy-duty applications and higher operational temperatures.

Understanding these technical distinctions ensures that gear systems receive the appropriate lubrication, enhancing performance and extending the lifespan of mechanical components. Always consult with a lubrication engineer or refer to the machinery’s specifications to select the most suitable gear oil for your application.