NLGI grade 2 is equivalent to a grease with an ASTM worked penetration (60 strokes) at 25 °C ranging from 265 to 295 tenths of a millimeter, and it has a consistency similar to peanut butter.
Understanding the NLGI (National Lubricating Grease Institute) consistency number helps classify greases based on their stiffness. This classification is crucial for selecting the right lubricant for various industrial and automotive applications.
Understanding Grease Consistency
The NLGI consistency number is determined by a test that measures how far a cone penetrates a grease sample under specific conditions. This "worked penetration" value, measured in tenths of a millimeter, indicates the grease's hardness or softness. A higher NLGI number signifies a firmer grease, while a lower number indicates a softer, more fluid grease.
Here's how NLGI grade 2 fits into the broader classification:
| NLGI Number | ASTM Worked Penetration (60 strokes) at 25 °C (tenths of a millimetre) | Consistency Food Analogy |
|---|---|---|
| 0 | 355-385 | Brown Mustard |
| 1 | 310-340 | Tomato Paste |
| 2 | 265-295 | Peanut Butter |
| 3 | 220-250 | Vegetable Shortening |
Key Characteristics of NLGI Grade 2 Grease
NLGI grade 2 is one of the most common and versatile grease grades used across numerous industries due to its balanced consistency.
- Moderate Firmness: It's firm enough to stay in place in many applications but soft enough to be pumped and distributed effectively by lubrication systems.
- Versatile Application: Often recommended for general-purpose lubrication in wheel bearings, chassis points, and various industrial machinery where good sealing and anti-leakage properties are desired.
- Food Analogy: The "peanut butter" analogy provides an intuitive understanding of its texture – not too runny, not too stiff, making it easy to spread but capable of holding its shape.
Importance in Lubrication
Choosing the correct NLGI grade is vital for optimal equipment performance and longevity.
- Lubrication Efficiency: A grease that is too stiff (higher NLGI) might not flow correctly to lubricate all parts, leading to starvation. A grease that is too soft (lower NLGI) might leak out, fail to form a protective seal, or not provide adequate film thickness under load.
- Sealing Properties: NLGI grade 2 offers good sealing properties, helping to keep contaminants out of bearings and other components.
- Pumpability: Its consistency allows it to be effectively dispensed by grease guns and automated lubrication systems, especially in moderate temperature ranges.
For more detailed information on grease consistency and classification, you can refer to the NLGI consistency number.
