|General features||Unit||iglidur® L250||test method|
|Max. humidity absorption at 23°C/50% R. H.||% weight||0,7||DIN 53495|
|Max. water absorption||% weight||3,9|
|Coefficient of surface friction, dynamic, against steel||μ||0,08–0,19|
|PV values max. (dry)||MPa x m/s||0,4|
|Bending E-module||MPa||1.950||DIN 53457|
|Tensile strength at +20 °C||MPa||67||DIN 53452|
|Maximum recommended surface pressure (20° C)||MPa||45|
|Shore D hardness||68||DIN 53505|
Physical and thermal properties
|Max. long term application temperature||°C||+90|
|Max. short term application temperature||°C||+180|
|Upper short-term ambient temperature1)||°C||+200|
|Lower application temperature||°C||-40|
|Heat conductivity||W/m x K||0,24||ASTM C 177|
|Coefficient of thermal expansion (at 23° C)||K-1 x 10-5||10||DIN 53482|
|Specific forward resistance||Ωcm||> 1010||DIN IEC 93|
|Surface resistance||Ω||> 1011||DIN 53482|
|1) Without additional load; no gliding movement; relaxation not excluded.|
iglidur® L250 is a bearing material for high rotary speeds, fast gliding movements and low coefficients of friction. The iglidur® L250 material can feature these advantages particularly with low loads. Applications which feature these advantages are fans, small motors, fast-running sensors or the magnet technology.
Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it. With increasing temperatures, the compressive strength of iglidur® L250 plain bearings decreases. Fig. 02 clarifies this connection.
iglidur® L250 has been developed especially for high surface speeds with low loads. Besides the physical limit, which is preset by the heating of the bearing, the coefficients of wear also act limitedly if rapidly high glide paths emerge at high peripheral speeds and the permitted wear limit is thus reached earlier. The maximum speeds can be gathered from Table 02.
|iglidur® L250||Operating temperature|
|Lower||- 40 °C|
|Upper, long-term||+ 90 °C|
|Upper, short-term||+ 180 °C|
|Secure axially in addition||+ 55 °C|
In the best pairing (with V2A shafts), friction coefficients of 0.14 are already reached with low loads. Coefficients of friction under 0.1 was already measured at 10 MPa. (Fig. 04 and 05).
|Coefficients of friction µ||0,08 - 0,19||0,09||0,04||0,04|
As seen in Figure 06, many shafts are recommendable for low loads and low rotations.
The good coefficients of friction are additionally retained over a wide range of recommendable surface finishes for shafts. For loads greater than 1 MPa, particular attention should be paid to the shaft material used.
|Alcohols||+ to 0|
|Fats, oils, without additives||+|
|Diluted acids||0 to -|
|Specific forward resistance||> 1010 Ωcm|
|Surface resistance||> 1011 Ω|
iglidur® L250 bearings are resistant to diluted alkalis and very weak acids as well as to solvents and all kinds of lubricants.
iglidur® L250 bearings are radiation resistant up to a radioactive intensity of 3 x 104 Gy. Higher radiation affects the material and may potentially lead to a notable lowering of value of an important mechanical property.
iglidur® L250 plain bearings change colour under the influence of UV rays. However, their properties do not deteriorate.
In application in vacuum, the potentially existent humidity is degassed. For this reason only the dry iglidur® L250 bearings are suitable for vacuum.
The bearings are electrically insulating.
|Maximum moisture absorption|
|by +23 °C/50 % r. F.||0,7 Wt.-%||Max. water absorption||3,9 Wt.-%|
Please take into account the humidity absorption in applications in which very minor bearing clearances occur.
|Up 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|
iglidur® L250 plain bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). After the installation in a housing with nominal diameter, the inner diameter of the bearing automatically adjusts to the E10 tolerance. In certain dimensions the tolerance in dependence on the wall thickness deviates from this (See delivery program )