iglidur® L250 - Material data

Mechanical specification
The maximum recommended surface pressure represents a mechanical material parameter. Conclusions on the tribology cannot be drawn from this. The compressive strength of iglidur® L250 plain bearings decreases with increasing temperatures. diagram. 02 illustrates this correlation.

diagram. 03 shows the elastic deformation of iglidur® L250 under radial load. Under the maximum recommended surface pressure of 45 MPa, the deformation is less than 3%. Plastic deformation can be neglected up to this value. However, it also depends on the duration of the impact.

Maximum surface speed

m/s

rotating

oscillating

linear

continuous

1

0,7

2

short-term

1,5

1,1

3

Table 02: Maximum surface speed

Permissible sliding speeds
iglidur® L250 has been developed precisely for high sliding speeds at low loads. In addition to the physical limit, which is specified by the bearing heating, the wear values also have a limiting effect if high sliding distances quickly occur at high circumferential speeds and the permissible wear limit is thus reached earlier. The maximum speeds can be found in Table 02.

iglidur® L250

Application temperature

below

- 40 °C

upper, long-term

+ 90 °C

upper, short-term

+ 180 °C

additional axial protection from

+ 55 °C

Table 03: Temperature limits for iglidur® L250

Temperatures
iglidur® L250 bearings can be used at temperatures of up to 180°C. It should be noted that mechanical securing of the bearing is recommended from temperatures of 55°C. Higher temperatures can cause the bearings to lose their press fit and move in the hole.

Medium

Resistance

Alcohols

+ to 0

Hydrocarbons

Greases, oils, not additivated

fuels

Diluted acids

0 to -

strong acids

-

Dilute bases

strong bases

0

+ resistant 0 conditionally resistant - not resistant
All data at room temperature [+20 °C]
Table 05: chemical resistance of iglidur® L250

Chemical resistance
iglidur® L250 plain bearings are resistant to diluted alkalis and very weak acids as well as to solvents and all types of lubricants.

**
Electrical specification

Volume resistivity

> 1010 Ωcm

surface resistance

> 1011 Ω

Radioactive radiation
Bearings made from iglidur® L250 are resistant to radiation up to a radiation intensity of 3 x 104 Gy. Higher radiation attacks the material and may lead to a noticeable reduction in the value of an important mechanical specification.

Maximum moisture absorption

at +23 °C/50 % room humidity.

0.7 % by weight

max. total moisture absorption

3.9 % by weight

Table 06: Moisture absorption

Moisture absorption
Please consider the moisture absorption in applications where the smallest bearing clearance is important.

Diameter****d1 [mm]

shaft h9**[mm]**

iglidur® L250****E10 [mm]

housing H7**[mm]**

to 3

0 - 0,025

+0,014 +0,054

0 +0,010

> 3 to 6

0 - 0,030

+0,020 +0,068

0 +0,012

> 6 to 10

0 - 0,036

+0,025 +0,083

0 +0,015

> 10 to 18

0 - 0,043

+0,032 +0,102

0 +0,018

> 18 to 30

0 - 0,052

+0,040 +0,124

0 +0,021

> 30 to 50

0 - 0,062

+0,050 +0,150

0 +0,025

> 50 to 80

0 - 0,074

+0,060 +0,180

0 +0,030

> 80 to 120

0 - 0,087

+0,072 +0,212

0 +0,035

> 120 to 180

0 - 0,100

+0,085 +0,245

0 +0,040

Table 07: Important tolerances according to ISO 3547-1 after press-fitting

Installation tolerances
iglidur® L250 plain bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). After installation in a mounting with nominal dimensions, the inner diameter of the bearing with E10 tolerance is set automatically. For certain dimensions, the tolerance deviates from this depending on the wall thickness (see product range).