iglidur® H2 - Material data

Materials table

General features Unit iglidur® H2 test method
Density g/cm³ 1,72
Colour Brown
Max. humidity absorption at 23°C/50% R. H. % weight 0,1 DIN 53495
Max. water absorption % weight 0,2
Coefficient of surface friction, dynamic, against steel µ 0,07 - 0,3
PV values max. (dry) MPa x m/s 0,58

Mechanical properties
Bending E-module MPa 10.300 DIN 53457
Tensile strength at +20 °C MPa 210 DIN 53452
compressive strength MPa 109
Maximum recommended surface pressure (20° C) MPa 110
Shore D hardness 88 DIN 53505

Physical and thermal properties
Max. long term application temperature °C +200
Max. short term application temperature °C +240
Lower application temperature °C -40
Heat conductivity [W/m x K] 0,24 ASTM C 177
Coefficient of thermal expansion (at 23° C) [K-1 x 10-5] 4 DIN 53752

Electrical properties
Specific forward resistance Ωcm > 1015 DIN IEC 93
Surface resistance Ω > 1014 DIN 53482
'Table 01: Material Data




Figure 01: Permitted PV values for iglidur® H2 bearings with 1 mm wall thickness in dry operation against a steel shaft, at 20°C, installed in a steel housing.

X = Surface speed [m/s]
Y = Load [MPa]

In applications with the iglidur® H2 bearings, economical aspects are in focus. It is the first time that it is possible to offer such a high-performance bearing for large volume applications with these technical advantages at such a low price: Temperatures till 200° C, permitted surface pressure till 110 N/mm, and excellent chemical resistance. iglidur® H2 bearings are self-lubricating and suitable for all motions.

Figure 02: Maximum recommended surface pressure dependent on the temperature (110 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. With increasing temperatures, the compressive strength of iglidur® H2 bearings decreases. Fig. 02 clarifies this connection.
 
Figure 03 shows the elastic deformation of iglidur® H2 with radial loads. Under the maximum recommended surface pressure of 110 MPa, the deformation at room temperature amounts to less than 3 %. The values for bending and compressive strengths lie above those of iglidur® H at room temperature.

m/s Rotary oscillating Linear
Constant 0,9 0,6 2,5
Short-term 1 0,7 3
Table 02: Maximum surface speeds

Permitted surface speeds

In the development of iglidur® H2, cost aspects and mechanical stability were in focus. The permitted surface speeds of this bearing are rather low, which primarily permits an application with slow movements or in intermittent service.

iglidur® H2 Operating temperature
Lower - 40 °C
Upper, long-term + 200 °C
Upper, short-term + 240 °C
Secure axially in addition + 110 °C
Table 03: Temperature limits for iglidur® H2

Temperatures

iglidur® H2 is an extremely temperature-resistant material. The short-term permitted maximum temperature is +240°C, and this enables the iglidur® H2 plain bearings to be used, for instance, in a paint drying process without further load. With increasing temperatures, however, the compressive strength of iglidur® H2 plain bearings decreases more strongly than in iglidur® H. The temperatures prevailing in the bearing system also have an influence on the bearing wear. The wear rises with increasing temperatures. An additional securing is recommended at temperatures higher than +110°C.

Figure 04: Coefficients of friction dependent on the surface speed, p = 0,75 MPa

X = Surface speed [m/s]
Y = Coefficient of friction μ
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 figures 04 to 06 clarify how the coefficients of friction of iglidur® H2 bearings alter with different surface speeds, loads and surface finishes.
iglidur® H2 Dry Grease Oil Water
Coefficients of friction µ 0,07 - 0,30 0,09 0,04 0,04
Table 04: Coefficients of friction for iglidur® H2 against steel (Ra = 1 µm, 50 HRC)

Fig. 06: Wear, rotating application with various Figure 06: Wear, rotating application with different 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

Regarding the wear resistance of combinations with iglidur® H2, it must be pointed out once again that this bearing was developed for high mechanical stability. The wear resistance however does not attain, with none of the bearing-shaft combinations, the values of iglidur® H370 with the corresponding shaft.
 
When the iglidur® H2 bearings are used, they should not be combined with hard-chromed shafts. Shafts made of CF53 and V2A are essentially better, as is found in Figures 06 and 07.
Fig. 07: Wear in oscillating and rotating Figure 07: Wear in pivoting and rotating applications with various shaft materials, p = 2MPa
 
Y = wear [μm/km]
 
A= Cf53
B= hard chrome-plated
C= V2A
D= St37
 
blue= rotating
pink= oscillating

Medium Resistance
Alcohols +
Hydrocarbons +
Greases, oils without additives +
Fuels +
Diluted acids + to 0
Strong acids + to -
Diluted bases +
Strong bases +
+ resistant      0 limited resistance      - not resistant
All specifications at room temperature[+20 °C]
Table 05: Chemical resistance of the iglidur® bearings H2


Electrical properties

Specific forward resistance > 1015 Ωcm
Surface resistance > 1014 Ω

Chemical resistance

iglidur® H2 bearings have a good resistance against chemicals. They are resistant to most lubricants. The iglidur® H2 is not affected by most weak organic and inorganic acids.

Radioactive rays

iglidur® H2 withstands both the neutron and gamma particle radiations without noticeable loss to its excellent mechanical properties. iglidur® H2 bearings are radiation resistant up to a radioactive intensity of 2 x 10² Gy.

UV-resistant

iglidur® H2 bearings alter under the influence of UV rays and other climatic influences. The surface becomes coarser, and the compressive strength declines. Therefore the use of iglidur® H2 in applications directly exposed to climatic conditions should be tested.

Vacuum

The low water elements degas in the vacuum. The use in vacuum is possible.

Electrical properties

iglidur® H2 bearings are electrically insulating.
 

Maximum moisture absorption
by +23 °C/50 % r. F. 0,1 weight-%
Max. water absorption 0,2 weight-%
Effect of moisture absorption on plain bearings Diagram 10: Effect of moisture absorption
 
X = Moisture absorption [weight %]
Y = Reduction of inside diameter [%]

humidity absorption / moisture absorption

The humidity absorption of iglidur® H2 bearings is about 0,1% in standard climatic conditions. The saturation limit in water is 0,2 %. iglidur® H2 is therefore the ideal material for wet areas.

Diameter
d1 [mm]
Shaft
h9 [mm]
iglidur® H2
F10 [mm]
Housing H7
[mm]
Up to 3 0 - 0,025 +0,006 +0,046 0 +0,010
> 3 to 6 0 - 0,030 +0,010 +0,058 0 +0,012
> 6 to 10 0 - 0,036 +0,013 +0,071 0 +0,015
> 10 to 18 0 - 0,043 +0,016 +0,086 0 +0,018
> 18 to 30 0 - 0,052 +0,020 +0,104 0 +0,021
> 30 to 50 0 - 0,062 +0,025 +0,125 0 +0,025
> 50 to 80 0 - 0,074 +0,030 +0,150 0 +0,030

Table 07: Important tolerances iaw. ISO 3547-1 after press-fitting.

Installation tolerances

iglidur® H2 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 F10 tolerance.

Delivery program

The iglidur® H2 bearings are manufactured according to order specifications. Please contact us for applications with large numbers of bearings made of iglidur® H2 as alternative to iglidur® H and H370.