|General Properties||Unit||iglide® A181||Testing Method|
|Max. moisture absorption at 73°F/50% r.h.||% weight||0.2||DIN 53495|
|Max. moisture absorption||% weight||1.3|
|Coefficient of surface friction, dynamic, against steel||µ||0.10 - 0.21|
|p x v value, max. (dry)||psl x fpm||8,750|
|Modulus of elasticity||psl||277,500||DIN 53457|
|Tensile strength at 68°F||psl||6,962||DIN 53452|
|Permissible static surface pressure (68°F)||psl||4,496|
|Shore D-hardness||76||DIN 53505|
Physical and Thermal Properties
|Max. long-term application temperature||°F||194|
|Max. short-term application temperature||°F||230|
|Minimum application temperature||°F||-58|
|Thermal conductivity||[W/m x K]||0.25||ASTM C 177|
|Coefficient of thermal expansion (at 73°F)||[K-1 x 10-5]||11||DIN 53752|
|Specific volume resistance||Ωcm||< 1012||DIN IEC 93|
|Surface resistance||Ω||< 1012||DIN 53482|
Bearings made from iglide® A181 are suitable for application in direct contact with food. This means they are the ideal solution for bearing applications on machines used by the food and packaging industry and medical equipment manufacturers, among others.
With increasing temperatures, the compressive strength of iglide® A181 plain bearings decreases. The recommended maximum surface pressure is a mechanical material parameter. No conclusions regarding the tribological properties can be drawn from this. The graph at the right shows the elastic deformation of iglide® A181 during radial loading. At the recommended maximum surface pressure of 4,496 psi the deformation is less than 3%. Plastic deformation is minimal up to this radial load. However, it is also a result of the service time.
iglide® A181 is developed for low surface speeds. Maximum speeds up to 158 fpm (rotating) and 689 fpm (linear) respectively are permitted for continuous use in dry operation. These given values indicate the limits at which an increase up to the continuous permissible temperature occurs. In practice these limit values are not always reached due to interactions.
|iglide® A181||Application Temperature|
|Minimum||- 58 °F|
|Max. long-term||+ 194 °F|
|Max. short-term||+ 230 °F|
|Additional axial securing||+ 140 °F|
The long-term upper temperature limit of +194°F permits broad use in applications with direct contact with food. As shown in the graph on the right, with increasing temperatures, the compressive strength decreases. When considering temperatures, the additional frictional heat in the bearing system must be taken into account.
Coefficient of friction and wear resistance alter with specific application parameters. For iglide® A181, the coefficient of friction μ is dependent on the surface speed of the shaft along with the shaft surface finish although generally speaking the effect is negligible as the table below represents. The coefficient of friction increases quickly with any load under 725 psi. As the load increases the coefficient of friction reduces drastically. For iglide® A181, a ground surface with an average between 8-64 rms is recommended, giving the user a wide range to work with.
|Coefficients of Friction µ||0,05 - 0,23||0,09||0,04||0,04|
The graphs show the test results of iglide® A181 bearings running against various shaft materials. Particular attention is paid in the food industry to corrosion-resistant shafts. The chart below shows that very low wear rates can be achieved in combination with these shafts. As with many of the iglide® materials, wear rate increases with otherwise identical parameters in rotation.
|Greases, oils without additives||+|
|Weak acids||0 to -|
|Strong alkaline||+ to 0|
|Specific volume resistance||< 1012 Ωcm|
|Surface resistance||< 1012 Ω|
iglide® A181 bearings can be used under various environmental conditions and in contact with numerous chemicals. Table 05 gives an overview of the chemical resistance of iglide® A181 bearings at room temperature.
Plain bearings made of iglide® A181 are resistant to radiation up to an intensity of 2 · 102 Gy.
iglide® A181 bearings are only conditionally resistant to UV radiation.
When used in a vacuum environment, the iglide® A181 bearings release moisture as a vapor. Therefore, only dehumidified bearings are suitable in a vacuum environment.
|Maximum moisture absorption|
|At 73 °F/50 % r.h.||0,2 weight-%|
|Max. water absorption||1,3 weight-%|
The moisture absorption of iglide® A181 bearings is approximately 0.2% in standard atmosphere. The saturation limit submerged in water is 1.3%. This must be taken into account for these types of applications.
|Length Tolerance (b1)||Length of Chamfer (f)|
|Length (mm)||Tolerance (h13)
|Based on d1|
|1 to 3||-0 /-140||f = 0.3 ➝ d1 1 - 6 mm|
|> 3 to 6||-0 /-180||f = 0.5 ➝ d1 > 6 - 12 mm|
|> 6 to 10||-0 /-220||f = 0.8 ➝ d1 > 12 - 30 mm|
|> 10 to 18||-0 /-270||f = 1.2 ➝ d1 > 30 mm|
|> 18 to 30||-0 /-330|
|> 30 to 50||-0 /-390|
|> 50 to 80||-0 /-460|
iglide® A181 plain bearings are meant to be oversized before being pressfit. After proper installation into a recommended housing bore, the inner diameter adjusts to meet our specified tolerances. Please adhere to the catalog specifications for housing bore and recommended shaft sizes. This will help to ensure optimal performance of iglide® plain bearings.