iglidur® F - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (105 MPa to +20 °C)
 
X = Temperature [°C]
Y = Load [MPa]

Figure 03: Deformation under load and temperatures

X = Load [MPa]
Y = Deformation [m/s]

Mechanical properties

Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it. The pressure resistance of iglidur® F plain bearings declines with increasing temperatures. Fig. 02 clarifies this connection. With the long-term permitted application temperature of +140°C, the permitted surface pressure still amounts to 50 MPa.
 
Diagram 03 shows the elastic deformation of iglidur® F during radial loading. Under the maximum recommended surface pressure of 105 MPa, the deformation amounts to less than 3,0%. A plastic deformation can be negligible up to this pressure load. It is however also dependent on the period of exposure.

Maximum surface speed

m/s	Rotating	Oscillating	Linear
Constant	0,8	0,6	3
Short-term	1,5	1,1	5

Permitted surface speeds

The maximum permitted surface speeds are based on the operation period and the type of motion. A bearing is the most stressed in long-term rotating motions. Here the maximum speed for the iglidur® F bearing is 0.8 m/s.

The maximum values specified in Table 11.2 are attained only at minimum pressure loads. In practice these limit values are not often attained due to interactions.

Figure 11.3: Maximum recommended surface pressure dependent on the temperature

iglidur® F	Application temperature
Lower	- 40 °C
Upper, long-term	+ 140 °C
Upper, short-term	+ 180 °C
Secure axially in addition	+ 105 °C

Table 03: Temperature limits for iglidur® F

Temperatures

The ambient temperatures strongly influence the properties of bearings. The pressure resistance of iglidur® F bearings declines with increasing temperatures. The wear also increases. Additional safety is required at temperatures over +105°C.

Figure 2.4: Coefficients of friction dependent on the surface speed, p = 0.75 MPa

Figure 05: Coefficients of friction dependent on the load, v = 0,01 m/s

X = Load [MPa]
Y = Coefficient of friction μ

Friction and wear

The coefficients of friction in the dry operation are not so favorable in iglidur® F bearings like in many other iglidur® materials. However iglidur® bearings can be lubricated without any problems, and iglidur® F bearings attain excellent results compared among the lubricated iglidur® bearings.

Friction and wear also depend to a high degree on the reverse partner. Figure 11.6 clearly shows how extremely smooth shafts raise the coefficient of friction of the bearing. The best suited is a smoothed surface with an average surface finish of Ra = 0.5 µm.

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

iglidur® F	Dry	Fat	Oil	Water
Coefficients of friction µ	0,1 - 0,39	0,09	0,04	0,04

Fig. 06: Wear, rotating application with various shaft materials p = 1 MPa, v = 0.3 m/s
 
X = shaft materials
Y = wear [μm/km]
 
A = Aluminum, hard-anodized
B = machining steel
C = Cf53
D = Cf53, hard chrome-plated
E = St37
F = V2A
G = X90

Shaft materials

Figures 06 and 07 show an excerpt of the results of tests with different shaft materials conducted with bearings made of iglidur® F. In the lowest load range, the hard-chromed shafts prove to be the most suitable counter partner in rotating applications with iglidur® F bearings.

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

+ resistant      0 limited resistance      - not resistant
All specifications at room temperature[+20 °C]
Table 05: Chemical resistance of the iglidur® bearings F

Electrical properties

Specific forward resistance	< 103 Ωcm
Surface resistance	< 102 Ω

Chemical resistance

iglidur® F bearings have a good resistance against chemicals. The particularly high resistance to lubricants is to be highlighted, even at high temperatures (around 120° C). Hence the iglidur® F bearings are particularly suitable for applications that call for lubrication necessitated by other parts.

The iglidur® F is not affected by most weak organic and inorganic acids.

The humidity absorption of iglidur® F bearings amounts to about 1,8% in standard climatic conditions. The saturation limit in water is 8,4%. This should be considered according to application conditions.

Radioactive rays

iglidur® F bearings are radiation resistant up to a radioactive intensity of 3 x 10² Gy.

UV-resistant

iglidur® F bearings are permanently resistant against UV rays.

Vacuum

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

Electrical properties

iglidur® F bearings are electrically conductive..

Maximum moisture absorption
by +23 °C/50 % r. F.	1,8 weight-%
Max. water absorption	8,4 weight-%

Table 06: Moisture absorption of iglidur® F

Diagram 10: Effect of moisture absorption
 
X = Moisture absorption [weight %]
Y = Reduction of inside diameter [%]

humidity absorption / moisture absorption

The humidity absorption of iglidur® 200 bearings amounts to about 1,8% in standard climatic conditions. The saturation limit in water is 8,4 %. This should be considered according to application conditions.

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

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® F D11 [mm]	Housing H7 [mm]
Up to 3	0 - 0,025	+0,020 +0,080	0 +0,010
> 3 to 6	0 - 0,030	+0,030 +0,105	0 +0,012
> 6 to 10	0 - 0,036	+0,040 +0,130	0 +0,015
> 10 to 18	0 - 0,043	+0,050 +0,160	0 +0,018
> 18 to 30	0 - 0,052	+0,065 +0,195	0 +0,021
> 30 to 50	0 - 0,062	+0,080 +0,240	0 +0,025
> 50 to 80	0 - 0,074	+0,100 +0,290	0 +0,030

Table 07: Important tolerances for iglidur® F bearings according to ISO 3547-1 after the press-fit.

Installation tolerances

iglidur® F 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 D11 tolerance. On certain dimensions, the tolerance varies from this as a function of the wall-thickness (see product range).