NLGI 2 grease is one of the most commonly used grease grades in industrial machinery, bearings, electric motors, pumps, conveyors and general mechanical equipment.
But what does the “2” actually mean?
It is often assumed that NLGI 2 refers to grease quality, thickness, temperature performance or load capacity. It does not.
NLGI 2 describes the consistency of the grease — essentially how firm or soft it is.
Understanding this distinction is important because two NLGI 2 greases can have completely different base oils, thickeners, temperature capabilities and load-carrying properties.
What is NLGI 2 grease?
NLGI stands for the National Lubricating Grease Institute.
The NLGI grading system classifies grease according to its consistency, based on worked penetration testing under ASTM D217.
NLGI 2 has a worked penetration of approximately 265–295 × 0.1 mm at 25°C. It is considered a medium-consistency grease. (NLGI)
The key point is:
NLGI 2 tells you how firm the grease is. It does not tell you how the grease will perform in every application.
An NLGI 2 grease can use different thickener systems, base oils and additive packages, and can be designed for anything from general-purpose lubrication to demanding industrial applications.
NLGI grease grades
The NLGI scale ranges from very soft NLGI 000 to very hard NLGI 6.
| NLGI Grade | Worked Penetration at 25°C | General Consistency |
|---|---|---|
| NLGI 000 | 445–475 | Very soft / semi-fluid |
| NLGI 00 | 400–430 | Very soft |
| NLGI 0 | 355–385 | Soft |
| NLGI 1 | 310–340 | Softer |
| NLGI 2 | 265–295 | Medium |
| NLGI 3 | 220–250 | Firm |
| NLGI 4 | 175–205 | Very firm |
The lower the NLGI number, the softer the grease.
NLGI 1 is softer than NLGI 2, while NLGI 3 is firmer. (NLGI)
Why is NLGI 2 so common?
NLGI 2 provides a useful balance between remaining in place and moving sufficiently during operation.
It is commonly found in:
- Electric motor bearings
- Pumps
- Conveyor bearings
- General industrial bearings
- Agricultural equipment
- Construction equipment
- Pins, bushes and shafts
- General mechanical machinery
However, NLGI 2 does not automatically mean a grease is suitable for every bearing or machine.
The equipment manufacturer's specification should always take priority.
NLGI 1 vs NLGI 2
The main difference is consistency.
NLGI 1 is softer than NLGI 2.
A softer NLGI 1 grease may be useful where easier grease movement is required, particularly in lower temperatures or some centralised lubrication systems.
NLGI 2 is commonly specified for conventional bearings and general industrial lubrication where a medium-consistency grease is required.
The correct choice depends on the equipment and operating conditions rather than assuming that one grade is universally better.
Does NLGI 2 mean the grease is thick?
Not exactly.
NLGI grade describes consistency, not the viscosity of the grease's base oil.
Two NLGI 2 greases can contain base oils with significantly different viscosities.
This is important because base-oil viscosity affects the lubricating film and suitability for different bearing speeds and loads.
Therefore, selecting grease based only on the NLGI number can result in the wrong product.
Does NLGI 2 mean the grease has high load capacity?
No.
An NLGI 2 grease is not automatically an EP (Extreme Pressure) grease.
EP additives can improve protection under heavy loads and boundary-lubrication conditions. Two NLGI 2 greases can therefore have very different load-carrying capabilities.
When selecting an industrial grease, also consider:
- EP performance
- Base oil viscosity
- Operating temperature
- Water
Why Shell Gadus?
Shell Gadus is a trusted range of industrial greases designed to provide reliable protection across a wide range of demanding applications. Its formulations are engineered to help protect bearings and machinery against wear, high loads, water contamination and temperature extremes. The range includes specialised greases for applications ranging from general industrial bearings to heavy-duty and high-temperature equipment. With Shell's extensive lubrication expertise and established reputation in industry, Gadus provides a strong combination of performance, reliability and technical support. For businesses looking to reduce equipment wear and improve lubrication reliability, Shell Gadus is a premium choice for industrial grease.
