iglidur® J2 - Material data

Material table

General specification

Unit

iglidur® J2

Test method

density

g/cm³

1,44

Colour

light yellow

max. Moisture absorption at 23°C/50% room humidity.

% by weight

0,2

DIN 53495

max. total moisture absorption

wt.-%

1,3

Sliding friction coefficient, dynamic, against steel

0,11 - 0,27

pv value, max. (dry)

MPa x m/s

0,23

Mechanical specification

flexural modulus

MPa

3.605

DIN 53457

flexural strength at 20°C

MPa

101

DIN 53452

Compressive strength

MPa

maximum recommended surface pressure (20°C)

MPa

Shore D hardness

n.b.

DIN 53505

Physical and thermal specification

Upper long-term application temperature

°C

+90

upper short-term application temperature

°C

+110

Lower application temperature

°C

-50

thermal conductivity

[W/m x K]

0,25

ASTM C 177

coefficient of thermal expansion (at 23°C)

[K-1 x 10-5]

DIN 53752

Electrical specification

Volume resistivity

Ωcm

> 1013

DIN IEC 93

surface resistance

> 1012

DIN 53482

Table 01: Material data

Download data sheet

Permissible pv value for iglidur® J2 plain bearing

iglidur® J2 is directly comparable with our classic iglidur® J in terms of the general mechanical and thermal specification. However, iglidur® J2 is superior to iglidur® J in terms of mechanical specifications, such as maximum recommended surface pressure. However, the wear resistance in dry operation is inferior.

Mechanical specification
The compressive strength of iglidur® J2 plain bearings decreases with increasing temperatures. diagram. 02 illustrates this correlation. The maximum recommended surface pressure represents a mechanical material parameter. Conclusions on the tribology cannot be drawn from this.

diagram. 03 shows the elastic deformation of iglidur® J2 under radial load. Possible plastic deformation depends, among other things, on the duration of the load.

load, surface pressure

Maximum surface speed

m/s

rotating

oscillating

linear

continuous

0,8

0,7

short-term

1,9

1,1

Table 02: Maximum surface speed

Permissible sliding velocities
iglidur® J2 is mainly suitable for low sliding speeds in dry operation, whereby the limit values specified in Table 02 can only be reached at very low pressure loads. At the specified speeds, friction can lead to an increase up to the limit of the permanently permissible temperature. In practice, these limit values cannot always be achieved.

iglidur® J2

Application temperature

lower

- 50 °C

upper, long-term

+ 90 °C

upper, short-term

+ 110 °C

additional axial protection from

+ 60 °C

Table 03: Temperature limits for iglidur® J2

Temperatures
The temperatures prevailing in the bearing system also have an influence on bearing wear. Wear increases with rising temperatures, and the effect is particularly noticeable from a temperature of +90 °C. An additional fuse is required at temperatures above +60 °C.

iglidur® J2

dry

Grease

oil

water

coefficient of friction µ

0,11 - 0,27

0,08

0,07

0,04

Table 04: Coefficient of friction for iglidur® J2 against steel (Ra = 1 μm, 50 HRC)

friction and wear
The coefficient of friction and wear resistance depend on the application parameters (diagrams 04 and 05).

Shaft materials
Friction and wear are also highly dependent on the mating partner. Shafts that are too smooth increase both the coefficient of friction and the wear of the bearing. diagram. 06 shows an extension of the results of tests with different shaft materials. In diagram. 06 it can be seen that iglidur® J2 delivers good wear values in rotation at 1 MPa, especially with free cutting steel. In dry running, the wear values on other shaft materials are significantly higher in some cases.
In contrast to many other iglidur®materials, the wear rate in swivelling is slightly higher compared to rotation with otherwise identical parameters (diagram 07).

Shaft materials

Medium

Resistance

Alcohols

hydrocarbons

Greases, oils, not additivated

fuels

Diluted acids

0 to -

strong acids

Dilute bases

strong bases

+ to 0

+ resistant 0 conditionally resistant - not resistant

All data at room temperature [+20 °C]
Table 05: chemical resistance of iglidur® J2

Further specification
chemical resistance
iglidur® J2 plain bearings are resistant to diluted alkalis and very weak acids as well as fuels and all types of lubricants. The low moisture absorption also permits use in wet or damp environments. Plain bearings made of iglidur® J2 are resistant to numerous cleaning agents commonly used in the food industry.

Radioactive radiationSliding bearingsmade of iglidur® J2 are resistant to radiation up to a radiation intensity of 3 - 102 Gy.

UV resistanceiglidur® J2 plain bearings discolour under the influence of UV rays. However, the hardness, compressive strength and wear resistance of the material do not deteriorate.

VacuumWhenused in a vacuum, any existing moisture content will outgas. Therefore, only dry bearing ausiglidur® J2 are suitable for vacuum.

Electrical specificationiglidur® J2 plain bearings are electrically insulating.

Volume resistivity

> 1013 Ωcm

surface resistance

> 1012 Ω

Maximum moisture absorption

at +23 °C/50 % room humidity.

0.2 % by weight

max. total moisture absorption

1.3 % by weight

Table 06: Moisture absorption of iglidur® J2

Moisture absorption
The moisture absorption of iglidur® J2 bearings is about 0.2 % in a normal climate. The saturation limit in water is 1.3 %. These values are so low that consideration of swelling due to moisture absorption is only necessary in extreme cases.

Diameter****d1 [mm]

shaft h9**[mm]**

iglidur® J2****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 for iglidur® J2 plain bearings according to ISO 3547-1 after press-fitting

Installation tolerances
iglidur® J2 bearings are standard bearings for shafts with tolerance (recommended minimum h9). The bearings are designed to be pressed into an H7-toleranced mounting; after installation in a mounting with nominal dimensions, the inner diameter of the bearing with E10 tolerance adjusts itself. Compared to the installation tolerance, the inner diameter changes depending on the moisture absorption.