The NLGI (National Lubricating Grease Institute) Grades classify lubricating greases based on their consistency, which is measured using a penetration test (ASTM D217). The NLGI grade number indicates the thickness or stiffness of the grease.
🧪 NLGI Consistency Grades
| NLGI Grade | Worked Penetration (mm/10) | Consistency Description | Typical Application |
|---|---|---|---|
| 000 | 445–475 | Fluid-like | Centralized lubrication systems, gearboxes |
| 00 | 400–430 | Semi-fluid | Enclosed gear systems, low-temp equipment |
| 0 | 355–385 | Very soft | Cold weather, centralized systems |
| 1 | 310–340 | Soft | Low temp or high-speed bearings |
| 2 | 265–295 | Normal (Most Common) | General-purpose bearings, automotive chassis |
| 3 | 220–250 | Firm | Electric motors, high-temp applications |
| 4 | 175–205 | Very firm | Heavy-duty industrial machinery |
| 5 | 130–160 | Hard | Specialized equipment, high load environments |
| 6 | 85–115 | Very hard | Very slow-moving or sealed-for-life components |
✅ Most Common Grades:
NLGI 1 and 3: Used for specific conditions like low temperatures or high heat.
NLGI 2: Widely used in automotive and industrial applications.