iglidur® G1 - Material data

Diagram 02: Recommended maximum surface pressure of a function of temperature (91 MPa at +20 °C)
 
X = Temperature [°C]
Y = Load [MPa]

Mechanical properties

With increasing temperatures, the compressive strength of iglidur® G1 plain bearings decreases. The diagram 02 shows this inverse relationship. With the long-term permitted application temperature of +180°C, the permitted surface pressure still amounts to 40 MPa. The recommended maximum surface pressure is a mechanical material parameter. No conclusions regarding the tribological properties can be drawn from this.

Diagram 03: Deformation under pressure and temperature
 
X = Load [MPa]
Y = Deformation [%]

Diagram 03 shows the elastic deformation of iglidur® G1 at radial loads. The plastic deformation is minimal up to a pressure of approximately 100MPa. However, it is also dependent on service time.

Maximum running speed

m/s	Rotating	Oscillating	linear
Long-term	1,3	1,0	5,0
Short-term	2,5	1,8	6,0

Table 02: Maximum surface speeds

Permissible surface speeds

iglidur® G1 has been developed for low to medium surface speeds. The maximum values shown in table 03 can only be achieved at low pressures. At the given speeds, friction can cause a temperature increase to the maximum continuously permissible level. In practice, though, this level is rarely reached due to varying application conditions.

iglidur® G1	Application temperature
Minimum	-40°C
Max. long-term	+180°C
Maximum, short-term	+220°C
In addition secure axially from	+120°C

Table 03: Temperature limits

Temperature

The ambient temperatures strongly influence the properties of plain bearings. The temperatures prevailing in the bearing system also have an influence on the wear. With increasing temperatures, the wear increases and this effect is significant when temperatures rise over +120°C. For temperatures over 120°C an additional securing of the bearings in the housing is required.

Diagram 04: Coefficient of friction as a function of the surface speed, p = 1MPa
 
X = Surface speed [m/s]
Y = Coefficient of friction μ

Diagram 05: Coefficient of friction as a function of the pressure, v = 0.01m/s
 
X = Load [MPa]
Y = Coefficient of friction μ

Friction and wear

The coefficient of friction μ of a plain bearing among other factors is influenced by the surface speed and the load (diagrams 04 and 05).
 

iglidur® G1	Dry	Greases	Oil	Water
C. o. f. µ	0,13 - 0,32	0,09	0,04	0,04

Table 04: Coefficient of friction against steel
(Ra = 1 µm, 50 HRC)

Diagram 06: Wear, rotating with different shaft materials, pressure, p = 1MPa, v = 0.3m/s
 
X = Shaft material
Y = Wear [μm/km]

Shaft materials

The friction and wear are also dependent, to a large degree, on the shaft material. Shafts that are too smooth, increase both the coefficient of friction and the wear of the bearing. For iglidur® G1 a ground surface with an average surface finish Ra = 0.8 µm is recommended. Diagram 06 shows results of testing different shaft materials with plain bearings made from iglidur® G1. It can be observed that iglidur® G1 achieves good to very good wear results with all shaft materials. The results for stainless steel types are most likely slightly lower. Diagram 07 compares the wear in rotating and pivoting applications. As with many of the iglidur® materials, wear rate is better in pivoting applications.

Diagram 07: Wear for oscillating and rotating applications with shaft material Cf53 hardened and ground steel, as a function of the load
 
X = Load [MPa]
Y = Wear [μm/km]

Chemicals	Resistance
Alcohol	+ up to 0
Hydrocarbons	+
Greases, oils without additives	+
Fuels	+
Diluted acids	0 to -
Strong acids	-
Diluted alkalines	+
Strong alkalines	0

+ resistant      0 limited resistance      - non-resistant
 
All information given at room temperature [+20°C]
Table 04: Chemical resistance

Moisture absorption

The moisture absorption of iglidur® G1 plain bearings in ambient conditions is approximately 0.2 % weight. The saturation limit in water is 1.7 %weight. This must be taken into account for these types of applications.

Radiation resistance

Plain bearings made from iglidur® G1 are resistant up to a radiation intensity of 3 · 10² Gy.

UV resistance

iglidur® G1 plain bearings are permanently resistant to UV radiation.

Vacuum

In vacuum, any present moisture is released as vapour. Use in vacuum is only possible with dehumidified iglidur® G1 bearings.

Electrical properties

Specific volume resistance	> 109 Ωcm
Surface resistance	> 109 Ω

Ø d1 [mm]	Housing H7 [mm]	Plain bearing F10 [mm]	Shaft h9 [mm]
to 3	+0,000 +0,010	+0,006 +0,046	-0,025 +0,000
> 3 to 6	+0,000 +0,012	+0,010 +0,058	-0,030 +0,000
> 6 to 10	+0,000 +0,015	+0,013 +0,071	-0,036 +0,000
> 10 to 18	+0,000 +0,018	+0,016 +0,086	-0,043 +0,000
> 18 to 30	+0,000 +0,021	+0,020 +0,104	-0,052 +0,000
> 30 to 50	+0,000 +0,025	+0,025 +0,125	-0,062 +0,000
> 50 to 80	+0,000 +0,030	+0,030 +0,150	-0,074 +0,000
> 80 to 120	+0,000 +0,035	+0,036 +0,176	-0,087 +0,000
> 120 to 180	+0,000 +0,040	+0,043 +0,203	+0,000 +0,100

Table 05: Important tolerances for plain bearings according to ISO 3547-1 after press-fit

 

Installation tolerances

iglidur® G1 plain bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). The bearings are designed for press-fit into a housing machined to a H7 tolerance. After being assembled into a nominal size housing, in standard cases the inner diameter automatically adjusts to the F10 tolerances. For particular dimensions the tolerance differs depending on the wall thickness (please see product range table).