iglide® J2 - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (6,672 psi to +68 °F)
 
X = Temperature [°F]
Y = Load [psi]

Figure 03: Deformation under load and temperatures
 
X = Load [psi]
Y = Deformation [%]

Mechanical properties

With increasing temperatures, the compressive strength of iglide® J2 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 iglide® J2 with radial loads. A potential plastic deformation depends, among other things, on the length of exposure.

Maximum surface speed

ft/min	Rotary	Oscillating	Linear
Constant	157	137	590
Short-term	374	216	984

Table 02: Maximum surface speeds

Permitted surface speeds

iglide® J2 is predominantly suitable for low speeds and dry running conditions; the limit values indicated in Table 02 can only be achieved at very low 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.

iglide® J2	Application temperature
Lower	- 122 °F
Upper, long-term	+ 194 °F
Upper, short-term	+ 230 °F
Secure axially in addition	+ 140 °F

Table 03: Temperature limits for iglide® J2

Temperatures

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 194°F temperature onward. An additional securing is recommended at temperatures higher than +140°F.

iglide® J2	Dry	Grease	Oil	Water
Coefficients of friction µ	0,11 - 0,27	0,08	0,07	0,04

Table 04: Coefficients of friction for iglide® J2 against steel (Ra = 1 µm, 50 HRC)

Friction and wear

The coefficient of friction and wear resistance depend on the application parameters (Fig. 04 and 05).

Fig. 06: Wear, rotating application with various shaft materials p = 145 psi, v = 59 ft/min
 
X = shaft materials
Y = wear [μm/km]
 
A = Aluminum, hard-anodized
B = machining steel

Shaft materials

Friction and wear also depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. Figure 06 shows an excerpt of the results of tests with different shaft materials. Fig. 06 shows that when rotating under 145 psi, iglide® J2 has the best wear coefficients with machining steel. During dry-running operations, the wear coefficients on other shafts are sometimes far higher.
Unlike many other iglidea® materials, the wear rate is slightly higher with pivoting movements than with rotational movements with otherwise identical parameters (Fig. 07).

Medium	Resistance
Alcohols	+
Hydrocarbons	+
Greases, oils without additives	+
Fuels	+
Diluted acids	0 to -
Strong acids	-
Diluted bases	+
Strong bases	+ to 0

+ resistant      0 conditionally resistant      - non-resistant
 
All specifications at room temperature[+68 °F]
Table 05: Chemical resistance of the iglide® bearings J2

 

 
Electrical propertiesiglide® J2 bearings are electrically insulating.

Specific forward resistance	> 1013 Ωcm
Surface resistance	> 1012 Ω

Further properties

Chemical resistance
iglige® J2 bearings are resistant to diluted alkali's 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. Plain bearings made from iglide® J2 are resistant to a wide range of cleaning agents used in the food industry.
 

Radioactive rays iglide® J2 bearings are radiation resistant up to a radioactive intensity of 3 • 10² Gy.
 

UV-resistant iglide® J2 bearings change color under the influence of UV rays. However the hardness, compressive strength and the wear resistance of the material do not degrade.
 

VacuumIn application in vacuum, the potentially existent moisture content is degassed. For this reason only the dry iglide® J2 bearings are suitable for vacuum.

Maximum moisture absorption

by 73 °F/50 % r. F.	0,2 Wt.-%
Max. water absorption	1,3 Wt.-%

Table 06: Humidity absorption of iglide® J2
 

Moisture absorption

The humidity absorption of iglide® J2 bearings amounts to about 0.2 % in standard climatic conditions. The saturation limit in water is 1,3 %. These values are so low that a moisture expansion need to be considered only in extreme cases.

Diameter d1 [mm]	Shaft h9 [mm]	iglide® J2 E10 [mm]	Housing H7 [mm]
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

Table 07: Important tolerances for iglide® J2 bearings according to ISO 3547-1 after the press-in.

Installation tolerances

iglide® J2 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.