iglide® Z - Material data

Maximum surface speed

fpm	Rotating	Oscillating	Linear
Constant	295	216	984
Short-term	689	492	1181

Permitted surface speeds

iglide® Z is suitable for both medium and - due to the high heat resistance - high speeds. The maximum values stated in the Table 21.2 can be attained only with minimum pressure loads. The specified values show the speed at which due to friction an increase in temperature up to the long-term permitted value can occur.

Figure 21.3: Maximum recommended surface pressure dependent on the temperature

Figure 21.4: Wear dependent on the temperature, rotating application with p = 109 psi (0.75 Mpa) and V = 98.5 fpm (0.5 m/s) (Cf53 shaft)

Temperatures

The short-term permitted maximum temperature amounts to 590° F (310° C) and thus attains the maximum heat resistance of any iglide® material.

With increasing temperatures, the compressive strength of iglide® Z bearings decreases. Fig. 21.3 clarifies this connection.

The temperatures prevailing in the bearing system also have an influence on the bearing wear. The wear rises with increasing temperatures.

Figure 21.4 shows that in the iglide® Z bearings the wear just doubles if the temperature rises to 302° F (150° C). Under high temperatures, iglide® Z is also the most wear-resistant material in dry operation.

Temperature limits

iglide® Z	Application temperature
Lower	- 148 °F
Upper, long-term	+ 482 °F
Upper, short-term	+ 590 °F

Figure 2.4: Coefficients of friction dependent on the surface speed, p = 109 psi (0.75 Mpa)

Friction and wear

The coefficient of friction alters only slightly like the wear resistance with increasing load.

Friction and wear also depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. iglide® Z proves to be relatively insensitive with regard to the shaft surface. The best suited is a smoothed surface with an average surface finish coefficient of friction 0.4 to 0.8 µm, if the friction should be minimized.

Coefficients of friction for iglide® Z against steel
(Ra = 1 µm, 50 HRC)

iglide® Z	Dry	Fat	Oil	Water
Coefficients of friction µ	0.06 - 0.14	0.09	0.04	0.04

Fig. 2.7: Wear, rotating application with different shaft materials, load p = 109 psi (0.75 Mpa), v = 98.5 fpm (0.5 m/s)

Figure 21.9: Wear with various shaft materials in the rotating application dependent on the load

Shaft materials

The diagrams show, in the lower load range, wear rates that are by all means similar to that of other indicated iglide® materials. In the upper range in contrast, iglide® Z outclasses all other materials in wear resistance. If a Cf53 shaft is used, the wear is only 15 µm/km even with 45 MPa.

With low loads, the iglide® Z bearings wear out less in pivoting applications than in rotating applications The V2A and hard-chromed shafts stand out in particular here. The value 0.5 µm/km is the lowest measured value with the shaft material V2A in pivoting applications with 2 MPa. With higher loads the behavior reverses, but even with 100 MPa, iglide® Z attains excellent coefficients of wear.

Please contact us in case the shaft material scheduled by you is not included in this diagram.

Important tolerances for iglide® Z bearings according to ISO 3547-1 after the press-fit.

Diameter d1 [mm]	Shaft h9 [mm]	iglide® Z F10 [mm]
Up to 0.019685	0 - 0.0009842	+0.0002362 + 0.0018110
> 0.118 to 0.236	0 - 0.0011811	+0.0003937 + 0.0022835
> 0.236 to 0.394	0 - 0.0014173	+0.0005118 + 0.0027953
> 0.394 to 0.709	0 - 0.0016929	+0.0006299 + 0.0033858
> 0.709 to 1.181	0 - 0.0020472	+0.0007874 + 0.0040945
> 1.181 to 1.969	0 - 0.0024409	+0.0009843 + 0.0049213

Installation tolerances

iglide® Z bearings are standard bearings for shafts with h-tolerance (recommended minimum h9).

After the installation in a housing bore with H7 tolerance, the inner diameter of the bearing automatically adjusts to F10 tolerance.

Medium	Resistance
Alcohol	0
Hydrocarbons	+
Fats, oils, without additives	+
Fuels	+
Diluted acids	+
Strong acids	-
Diluted bases	+
Strong bases	-

+ resistant      0 conditionally resistant      - non-resistant

Figure 21.12: Influence of humidity absorption of iglide® Z bearings

Electrical properties

Specific forward resistance	> 1011 Ωcm
Surface resistance	> 1011 Ω

Chemical resistance

iglide® Z bearings have a good resistance against chemicals. They possess an excellent resistance to organic solvents, fuels, oils and fats. The material is only partially resistant to weak acids. The humidity absorption of iglide® Z bearings amounts to about 0.3% in standard climatic conditions. The saturation limit in water is 1.1%.

Radioactive rays

iglide® Z bearings are radiation resistant up to a radioactive intensity of 1 x 10⁵ Gy.

UV-resistant

With UV radiation, the tribological properties (wear) of the iglide® Z bearings drop by about 50%.

Vacuum

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

Electrical properties

iglide® Z bearings are electrically insulating.