|Genera l features||Unit||iglidur® K||test method|
|Max. humidity absorption at 23°C/50% R. H.||% weight||0,1||DIN 53495|
|Max. water absorption||% weight||0,6|
|Coefficient of surface friction, dynamic, against steel||µ||0,06 - 0,21|
|pv values (dry)||MPa x m/s||0,30|
|Bending E-module||MPa||3.500||DIN 53457|
|Tensile strength at +20 °C||MPa||80||DIN 53452|
|Maximum recommended surface pressure (20° C)||MPa||50|
|Shore D-hardness||72||DIN 53505|
Physical and thermal properties
|Max. long term application temperature||°C||+170|
|Max. short term application temperature||°C||+240|
|Minimum application temperature||°C||-40|
|thermal / heat conductivity||W/m x K||0,25||ASTM C 177|
|Coefficient of thermal expansion (at 23° C)||K-1 x 10-5||3||DIN 53752|
|Specific forward resistance||Ωcm||> 1012||DIN IEC 93|
|surface resistance||Ω||> 1012||DIN 53482|
iglidur® K is characterised by its good wear behaviour at low moisture absorption and good thermal and mechanical properties. This supports a very universal application spectrum.
With increasing temperatures, the compressive strength of iglidur® K plain bearings decreases. Fig. 02 clarifies this connection. Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it.
Figure 03 shows the elastic deformation of iglidur® K with radial loads. Under the maximum recommended surface pressure of 50 MPa, the deformation amounts to less than 3%. A potential plastic deformation depends, among other things, on the length of exposure.
iglidur® K has been developed for low to medium surface speeds. The maximum values stated in Table 02 can be attained only with minor pressure loads. At the specified speeds, an increase in temperature up to the long-term permitted value can occur due to friction. In practice these limit values are not always reached due to interactions.
|iglidur® K||Application temperature|
|Upper, long-term||+170 °C|
|Upper, short-term||+240 °C|
|Secure axially in addition||+70 °C|
The temperatures prevailing in the bearing system also have an influence on the bearing wear. The wear increases with rising temperatures, and the influence is especially marked from 100°C temperature onwards. An additional securing is recommended at temperatures higher than +70°C.
|Coefficients of friction µ||0,06-0,21||0,09||0,04||0,04|
Just like the wear resistance, the coefficient of friction µ also alters with the load (Fig. 04 and 05).
Friction and wear also depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear.
A smoothed surface with an average surface finish Ra = 0.15–0.20 µm is best suited for iglidur® K.
Figure 06 displays a summary of the results of tests with different shaft materials, which were conducted with iglidur® K plain bearings. In this connection it is important to note that with increasing loads, the recommended hardness of the shaft increases. The "soft" shafts tend rather to wear themselves and thus increase the wear of the entire system, if the loads exceed 2 MPa. The comparison of rotating and pivoting movements shows that the wear is virtually identical up to a load of 5 MPa. Higher the load, the greater is the difference (Fig. 07).
|Alcohols||+ to 0|
|Fats, oils, without additives||+|
|Diluted acids||0 to -|
|Specific forward resistance||> 1012 Ωcm|
|Surface resistance||> 1012 Ω|
iglidur® K bearings are resistant to diluted alkalis and very weak acids as well as to fuels and all kinds of lubricants. The low humidity absorption allows them to be used in wet or humid environment.
iglidur® K plain bearings are radiation resistant up to a radiation intensity of5 x 102 Gy.
iglidur® K plain bearings change colour under the influence of UV radiation. However, the material properties do not change.
In vacuum, iglidur® K degases. The use in vacuum is possible only limitedly.
|by +23 °C/50 % r. F.||0,1 Wt.-%|
|Max. water absorption||0,6 Wt.-%|
The humidity absorption of iglidur® K bearings amounts to about 0.1 % in standard climatic conditions. The saturation limit in water is 0,6 %. These values are so low that a moisture expansion need to be considered only in extreme cases.
|Up to 3||0 - 0,025||+0,014 +0,054||0 +0,010|
|> 3 bis 6||0 - 0,030||+0,020 +0,068||0 +0,012|
|> 6 to 10||0 - 0,043||+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 bis 180||0 - 0,100||+0,085 +0,245||0 +0,040|
Table 07: Important tolerances iaw. ISO 3547-1 after press-fitting
iglidur® K bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). The bearings are designed for press-fit in a housing with h7 tolerance. After the installation in a housing with nominal diameter, the inner diameter of the bearing automatically adjusts to the E10 tolerance. Compared to the installation tolerance, the inner diameter varies according to moisture absorption.