INDUSTRIAL LUBRICANT CLASSIFICATION

ISO (International Standards Organisation) Viscosity Classification

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