What Is NLGI Grade?
The NLGI grade is a standardized classification system from the National Lubricating Grease Institute that rates grease consistency (stiffness) on a scale from 000 (semi-fluid) to 6 (block-hard). The grade is determined by the worked penetration test per ASTM D217.
NLGI Grade Scale
| Grade | Consistency | Typical Use |
|---|---|---|
| 000-0 | Semi-fluid | Centralized systems, gearboxes |
| 1 | Soft | Automated dispensers, low-temp |
| 2 | Normal | Standard rolling bearings |
| 3 | Firm | Vertical shafts, high vibration |
Learn more in the Grease Selection Guide.
Frequently Asked Questions
What NLGI grade should I use for bearings?
NLGI Grade 2 is the standard for most rolling bearings. Use Grade 1 for centralized lubrication systems (needs to flow through pipes). Use Grade 3 for vertical shafts or high-vibration applications where grease must stay in place. Grades 0 and 00 are used in gearbox lubrication.
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