|General features||Unit||iglide® L250||Test method|
|Max. moisture absorption at 73° F/50% R. H.||Wt.-%||0.7||DIN 53495|
|Max. moisture absorption||Wt.-%||3.9|
|Coefficient of friction, dynamic against steel||µ||0.08 - 0.19|
|p x v value, max. (dry)||psi x fpm||11,500|
|Modulus of elasticity||psi||282,800||DIN 53457|
|Tensile strength at 68° F||psi||9,718||DIN 53452|
|Maximum recommended surface pressure (68° F)||psi||6,527|
|Shore D hardness||68||DIN 53505|
Physical and thermal properties
|Upper long-term application temperature||°F||194|
|Upper short-term application temperature||°F||356|
|Lower application temperature||°F||-40|
|Thermal conductivity||[W/m x K]||0.24||ASTM C 177|
|Coefficient of thermal expansion (at 73° F)||[K-1 x 10-5 ]||10||DIN 53752|
|Specific volume resistance||Ωcm||> 1010||DIN IEC 93|
|Surface resistance||Ω||> 1011||DIN 53482|
For iglide® L250 plastic bushings with 0.03 inches (1 mm) wall thickness in dry operation against a steel shaft, at 68° F, installed in a steel housing.
iglide® L250 is a bushing material for high rotary speeds, fast gliding movements and super coefficients of friction. The iglide® 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.
iglide® L250 has been developed especially for high surface speeds with low loads. Besides the physical limit, which is preset by the heating of the bushing, the coefficients of wear also act limitingly if rapidly high glide paths emerge at high peripheral speeds and the permitted wear limit is thus reached earlier. The great advantages of the iglide® L250 plastic bushings are seen right here. The wear rate is very low, thus making the material an ideal solution for extreme glide paths. The maximum speeds are show in the table to the left.
The iglide® L250 plastic bushings can be used in temperatures from -40° F up to 194° F. The short-term maximum temperature is 356° F. Note that a mechanical securing of the bushing is recommended from temperatures of 131° F. Higher temperatures can also cause the bushing to lose its press-fit seating and move in the housing.
|iglide® L250||Application temperature|
|Lower||- 40 °F|
|Upper, short-term||+356 °F|
|Additional axial securing||+131 °F|
Low coefficients of friction are a big influence on the excellent characteristics of iglide® L250 plastic bushings. The best pairing of iglide® L250 is with 304 stainless steel shafts where coefficient of friction of 0.14 are already attained at low loads. Coefficients of friction below 0.1 have already been measured for values below 1,450 psi. In order to convey the excellent wear values to the application, loads in excess of 725 psi should be avoided.
|Coefficients of friction µ||0.08 - 0.19||0.09||0.04||0.04|
As shown in the graphs, a variety of shafts can be used at low loads and low rotation. The good coefficients of friction are maintained across a wide range of recommended shaft roughness values. With regards to loads greater than 145 psi the shaft material selection becomes more important.
|Shaft h9 |
|iglide® L250 |
|Up to 0.5||0 - 0,025||+0,014 + 0,054|
|> 3 to 6||0 - 0,030||+0,020 + 0,068|
|> 6 to 10||0 - 0,036||+0,025 + 0,083|
|> 10 to 18||0 - 0,043||+0,032 + 0,102|
|> 18 to 30||0 - 0,052||+0,040 + 0,124|
|> 30 to 50||0 - 0,062||+0,050 + 0,150|
|Alcohol||+ to 0|
|Greases, oils, without additives||+|
|Weak acids||0 to -|
|Specific volume resistance||> 1010 Ωcm|
|Surface resistance||> 1011 Ω|
iglide® L250 plastic bushings are resistant to diluted alkalis and very weak acids as well as to solvents and all kinds of lubricants.
Please take into account the humidity absorption in applications in which very minor bushing clearances occur.
iglide® L250 plastic bushings 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.
iglide® L250 plastic bushings change color under the influence of UV rays. However the hardness, compressive strength and the wear resistance of the material do not degrade.
In application in vacuum, the potentially existent humidity is degassed. For this reason only the dry iglide® L250 plastic bushings are suitable for vacuum.
The bushings are electrically insulating.