Classification
The following table shows the NLGI classification and compares each grade with household products of similar consistency.
| NLGI number | ASTM worked (60 strokes) penetration at 25 °C tenths of a millimetre |
Appearance | Consistency food analog |
|---|---|---|---|
| 000 | 445-475 | fluid | cooking oil |
| 00 | 400-430 | semi-fluid | apple sauce |
| 0 | 355-385 | very soft | brown mustard |
| 1 | 310-340 | soft | tomato paste |
| 2 | 265-295 | "normal" grease | peanut butter |
| 3 | 220-250 | firm | vegetable shortening |
| 4 | 175-205 | very firm | frozen yogurt |
| 5 | 130-160 | hard | smooth pate |
| 6 | 85-115 | very hard | cheddar cheese |
Common greases are in the range 1 through 3. Those with a NLGI No. of 000 to 1 are used in low viscosity applications. Examples include enclosed gear drives operating at low speeds and open gearing. Grades 0, 1 and 2 are used in highly loaded gearing. Grades 1 through 4 are often used in rolling contact bearings. Greases with a higher number are firmer, tend to stay in place and are a good choice when leakage is a concern.
Read more about this topic: NLGI Consistency Number