|Genera l features||Unit||iglidur® H4||test method|
|Max. humidity absorption at 23°C/50% R. H.||% weight||0,1||DIN 53495|
|Max. water absorption||% weight||0,2|
|Coefficient of surface friction, dynamic, against steel||μ||0,08-0,25|
|pv value, max. (dry)||MPa x m/s||0,7|
|Bending E-module||MPa||7.500||DIN 53457|
|Tensile strength at +20 °C||MPa||120||DIN 53452|
|Compressive strength at 20°C||MPa||50|
|Maximum recommended surface pressure (20° C)||MPa||65|
|Shore D-hardness||80||DIN 53505|
Physical and thermal properties
|Max. long term application temperature||°C||+200|
|Max. short term application temperature||°C||+240|
|Minimum application temperature||°C||-40|
|thermal / heat conductivity||W/m x K||0,24||ASTM C 177|
|Coefficient of thermal expansion (at 23° C)||K–1 x 10–5||5||DIN 53752|
|Specific forward resistance||Ωcm||> 1013||DIN IEC 93|
|surface resistance||Ω||> 1012||DIN 53482|
|1) Without additional load; no gliding movement; relaxation not excluded.|
iglidur® H4 bearings stand for high carrying capacity, good abrasion resistance and good temperature resistance, besides the obvious economic factors. Temperatures up to +200°C, permitted surface pressure of up to 65 MPa and excellent chemical resistance are just some of the essential attributes. Solid lubricants lower the coefficient of friction and support the wear resistance, which was essentially improved compared to the likewise cost-efficient iglidur® H2 bearings. iglidur® H4 bearings are self-lubricating and suitable for all motions.
Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it. With increasing temperatures, the compressive strength of iglidur® H4 bearings decreases. Fig. 02 clarifies this connection. With the long-term permitted application temperature of +200°C, the permitted surface pressure still amounts to 7 MPa.
Figure 03 shows the elastic deformation of iglidur® H4 with radial loads.
In contrast to the similarly cost-efficient iglidur® H2 bearings, the iglidur® H4 has an essentially favorable coefficient of friction. This accounts for the higher permitted surface speeds that can be attained with these bearings. In the dry operation, long-term speeds of
1 m/s are possible. The speeds stated in Table 02 are limit values for the lowest bearing loads. With higher loads, the permitted speed drops with the extent of the load due to the limitations by the p x v value.
|iglidur® H4||Operating temperature|
|Lower||- 40 °C|
|Upper, long-term||+ 200 °C|
|Upper, short-term||+ 240 °C|
|Secure axially in addition||+ 110 °C|
iglidur® H4 is a temperature-resistant material. As a result, iglidur® H4 bearings can be used in applications in which bearings are subjected to a drying process without further load. With increasing temperatures, the compressive strength of iglidur® H4 bearings however decreases. The additional frictional heat in the bearing system must be taken into account. An additional securing is recommended at temperatures higher than +110°C.
The coefficient of friction of iglidur® H4 bearings is very low (Fig. 04 and 05). However it must be noted that an extremely coarse gliding partner increases the friction.
|Coefficients of friction µ||0,08 - 0,25||0,09||0,04||0,04|
Particularly given the high number of usable shaft materials, the iglidur® H4 is the economical alternative to many other high-temperature bearings. The important thing is however the selection of the suitable shaft material. It cannot be generally stated that iglidur® H4 is better suited for hard or soft shafts. Tests have however shown that pivoting motions yield better wear data. In rotating applications, the wear increases markedly from 10 MPa.
|Greases, oils without additives||+|
|Diluted acids||+ to 0|
|Strong acids||+ to -|
|Specific forward resistance||> 1013 Ωcm|
|Surface resistance||> 1012 Ω|
iglidur® H4 bearings have a good resistance against chemicals. They are resistant to most lubricants.
The iglidur® H4 is not affected by most weak organic and inorganic acids.
iglidur® H4 withstands both the neutron and gamma particle radiations without noticeable loss of its excellent mechanical properties.
iglidur® H4 bearings are radiation resistant up to a radiation intensity of 2 x 102 Gy.
iglidur® H4 bearings alter under the influence of UV rays and other climatic influences. The surface becomes coarser, and the compressive strength declines. Therefore the use of iglidur® H4 in applications directly exposed to climatic conditions should be tested.
The low water elements degas in the vacuum. The use in vacuum is possible.
iglidur® H4 bearings are electrically insulating.
|Max. humidity absorption|
|by +23 °C/50 % r. F.||0,1 weight-%|
|Max. water absorption||0,2 weight-%|
The humidity absorption of iglidur® H4 bearings is about 0.1% in standard climatic conditions. The saturation limit in water is 0,2 %. iglidur® H4 is therefore the ideal material for wet areas.
|Up to 3||0 - 0,025||+0,006 +0,046||0 +0,010|
|> 3 to 6||0 - 0,030||+0,010 +0,058||0 +0,012|
|> 6 to 10||0 - 0,036||+0,013 +0,071||0 +0,015|
|> 10 to 18||0 - 0,043||+0,016 +0,086||0 +0,018|
|> 18 to 30||0 - 0,052||+0,020 +0,104||0 +0,021|
|> 30 to 50||0 - 0,062||+0,025 +0,125||0 +0,025|
|> 50 to 80||0 - 0,074||+0,030 +0,150||0 +0,030|
iglidur® H4 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 F10 tolerance. In certain dimensions the tolerance in dependence on the wall thickness deviates from this (See delivery program )