The ISO viscosity classification uses mm2/s (cSt) and relates to viscosity at 40°C. It consists of a series of 18 viscosity brackets between 1.98 mm2/s and 1650 mm2/s, each of which is defined by a number.
ISO Viscosity Grade |
Kinematic Viscosity at 40°C (mm2/s |
||
Minimum |
Maximum |
Mid-point |
|
2 |
1.98 |
2.42 |
2.20 |
3 |
2.88 |
3.52 |
3.20 |
5 |
4.14 |
5.06 |
4.60 |
7 |
6.12 |
7.48 |
6.80 |
10 |
9.0 |
11.0 |
10.0 |
15 |
13.5 |
16.5 |
15.0 |
22 |
19.8 |
24.2 |
22.0 |
32 |
28.8 |
35.2 |
32.0 |
46 |
41.4 |
50.6 |
46.0 |
68 |
61.2 |
74.8 |
68.0 |
100 |
90.0 |
110 |
100 |
150 |
135 |
165 |
150 |
220 |
198 |
242 |
220 |
320 |
288 |
352 |
320 |
460 |
414 |
506 |
460 |
680 |
612 |
748 |
680 |
1000 |
900 |
1100 |
1000 |
1500 |
1350 |
1650 |
1500 |