- 23 -
EN
951-180-074-EN Version
03, last updated
2019 / 07
4
4.
Technical data
See Chapters 4.7.1 to 4.7.2
The curves shown in both figures are based on a viscosity index
(VI)
of VI ~ 95, approximately corresponding to standard mineral oil. The
viscosity index describes the slope of the curve and thus the viscosi-
ty-temperature relationship at temperatures other than +40°C.
The lines appear straight because a logarithmic scale was selected
for the ordinate so that the slope of the curves can be determined
easily based on 2 measuring points.
Important note:
4.7 Viscosity-temperature relationship of oils with different rated viscosity
4.7.1 Viscosity range from 2.6 to 50 mm
2
/s
Viscosity range from 2.6 to 50 mm
2
/s, Fig. 7
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
IS
O
VG
320
100
32
10
3
Temperatur °C
Viscosity class *)
ISO VG is approx.
3, 10
Spindle oils
32, 100 Normal machine oils
320
Medium-heavy machine oils
1000
Gear oil or similar
*) The values correspond to the midpoint
viscosity at 40°C in mm
2
/s
Viscosity range from 50 to 2000 mm
2
/s, Fig. 8
Kinetic visc
osit
y [mm
2
/s
]
4.7.2 Viscosity range from 50 to 2000 mm
2
/s
40
60
70
80
90
100
150
200
300
400
500
700
20 000
14 000
10 000
5 000
7000
2 000
3000
4000
1 000
1 500
IS
O
VG
1000
320
100
32
10
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95 100
50
Temperatur °C
The change in the viscosity of oils is disproportionately greater in
lower temperature ranges than in higher temperature ranges. For
example, an oil with a rated viscosity of 100 undergoes the following
viscosity change in different temperature ranges at the same tem-
perature difference:
at +80°C = 18 mm
2
/s
at +10°C = 875 mm
2
/s
versus:
at +75°C = 21 mm
2
/s change of 3 mm
2
/s
at + 5°C = 1450 mm
2
/s change of 575 mm
2
/s.
Kinetic visc
osit
y [mm
2
/s
]
Temperature [°C]
Temperature [°C]