Grease Technical Data Demystified

Grease Technical Data Demystified

When selecting the right grease for your machinery, understanding its technical specifications is crucial. Grease data sheets contain critical parameters that determine performance, longevity, and compatibility with your equipment. However, terms like NLGI grade, base oil viscosity, and dropping point can be confusing without proper context.

This guide breaks down the most important grease technical data points, explaining what they mean and how they impact your lubrication strategy.

Key Grease Technical Specifications Explained

1. NLGI Grade (Consistency)

The National Lubricating Grease Institute (NLGI) grade indicates grease consistency, ranging from 000 (fluid) to 6 (very hard). Common grades include:

NLGI 2: Standard for most industrial applications

NLGI 0 or 1: Used in centralized lubrication systems

NLGI 3: For high-load, low-speed applications

Why it matters: Choosing the wrong NLGI grade can lead to poor lubrication or excessive grease hardening.

2. Base Oil Viscosity (ISO VG)

The base oil viscosity (measured in cSt at 40°C) affects:

Film strength (thicker oil = better load protection)

Temperature performance (low-viscosity oils work better in cold environments)

Example: A grease with ISO VG 220 is thicker than one with ISO VG 100, making it better for heavy machinery.

3. Dropping Point (ASTM D2265)

The dropping point is the temperature at which grease liquefies and loses structure.

Standard greases: ~180–200°C

High-temperature greases: 250°C+

Why it matters: If grease exceeds its dropping point, it can leak out of bearings, causing lubrication failure.

4. Thickener Type (Lithium, Calcium, Polyurea, etc.)

The thickener determines grease stability and compatibility. Common types:

Lithium (Li): General-purpose, good water resistance

Calcium (Ca): Excellent water resistance, used in marine applications

Polyurea: Long-life, high-temperature performance

Why it matters: Mixing incompatible thickeners can cause grease breakdown.

5. Oxidation Stability (ASTM D942)

Measures how well grease resists degradation when exposed to oxygen.

Longer oxidation life = longer service intervals

Why it matters: Poor oxidation stability leads to grease hardening and increased wear.

6. Four-Ball Wear Test (ASTM D2266)

Evaluates anti-wear properties by measuring scar diameter on test balls under load.

Lower scar diameter = better protection

Why it matters: Critical for high-load applications like gearboxes and bearings.

How to Use Grease Technical Data for Better Lubrication

Match NLGI grade to your application (e.g., NLGI 2 for bearings, NLGI 0 for cold climates).

Check base oil viscosity—thicker oils for heavy loads, thinner oils for high speeds.

Verify temperature limits (dropping point and low-temperature torque).

Ensure thickener compatibility if switching grease types.

Prioritize oxidation stability for longer relubrication intervals.

Optimize Performance with the Right Grease

Understanding grease technical data ensures you select the best lubricant for your equipment, preventing premature failure and costly downtime. Whether you need high-temperature stability, extreme pressure protection, or long-lasting performance, the right grease specification makes all the difference.

At Conlysen, we specialize in high-performance lubricants tailored to your machinery’s needs. Our experts can help you interpret technical data and recommend the ideal grease for your application.