iglidur® R - Material data

Materials table

General features	Unit	iglidur® R	test method
Density	g/cm³	1,39
Colour		Dark red
Max. humidity absorption at 23°C/50% R. H.	% weight	0,2	DIN 53495
Max. water absorption	% weight	1,1
Coefficient of surface friction, dynamic, against steel	µ	0,09 - 0,25
PV values max. (dry)	MPa x m/s	0,27
Mechanical properties
Bending E-module	MPa	1.950	DIN 53457
Tensile strength at +20 °C	MPa	70	DIN 53452
compressive strength	MPa	68
Maximum recommended surface pressure (20° C)	MPa	23
Shore D hardness		77	DIN 53505
Physical and thermal properties
Max. long term application temperature	°C	+90
Max. short term application temperature	°C	+110
Lower application temperature	°C	-50
Heat conductivity	[W/m x K]	0,25	ASTM C 177
Coefficient of thermal expansion (at 23° C)	[K^-1 x 10^-5]	11	DIN 53752
Electrical properties
Specific forward resistance	Ωcm	> 10¹²	DIN IEC 93
Surface resistance	Ω	> 10¹²	DIN 53482

'Table 01: Material Data

Figure 01: Permitted PV values for iglidur® R 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]

The development of the iglidur® R as a bearing material focused on high performance and very low cost. Especially in the dry operation low coefficients of friction and wear were to be attained. The PTFE- and silicon-free material achieves extremely low coefficients of friction in dry operation and runs largely free of stick-slip effects.

Figure 02: Maximum recommended surface pressure dependent on the temperature (23 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® R plain bearings decreases. Fig. 02 clarifies this connection.

Figure 03 shows the elastic deformation of iglidur® R with radial loads. Under the maximum permitted load of 23 MPa, the deformation amounts to 4%. A plastic deformation can be negligible up to this value. It is however also dependent on the period of exposure.

Maximum surface speed

m/s	Rotary	oscillating	Linear
Constant	0,8	0,6	3,5
Short-term	1,2	1	5

Table 02: Maximum surface speeds

Permitted surface speeds

iglidur® R bearings are suitable for high surface speeds. Speeds of up to 10 m/s are permitted in linear motions! Here too the specified maximum values can be achieved 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.

Surface speed

p x v value and lubrication

iglidur® R	Operating temperature
Lower	- 50 °C
Upper, long-term	+ 90 °C
Upper, short-term	+ 110 °C
Secure axially in addition	+ 50 °C

Table 03: Temperature limits for iglidur® R

Temperatures

With increasing temperatures, the compressive strength of iglidur® R plain bearings decreases. Fig. 02 clarifies this connection. The temperatures prevailing in the bearing system also have an influence on the bearing wear. An additional securing is recommended at temperatures higher than +50°C.

Temperatures, coefficient of thermal expansion

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

X = Surface speed [m/s]
Y = Coefficient of friction μ

Friction and wear

The coefficient of friction declines like the wear resistance with increasing load. iglidur® R is suitable for applications in which high pv values are induced mainly through the high surface speed and not as much through the surface pressure. Less distinct is the dependency of the coefficient of friction of the iglidur® R bearings on the shaft surface.

iglidur® R	Dry	Grease	Oil	Water
Coefficients of friction µ	0,09 - 0,25	0,09	0,04	0,04

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

Coefficients of friction

Wear resistance

Figure 05: Coefficients of friction dependent on the load, v = 0.01 m/s

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

Fig. 06: Wear, rotating application with different shaft materials, load p = 1 MPa, v = 0.3 m/s

X = Shaft material
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 display a summary of the results of tests with different shaft materials conducted with bearings made of iglidur® R. At 0.3m/s and 1 MPa, the X90 and Cf53 shafts are the best gliding partners. With increasing loads the iglidur® R bearings feature the best wear behavior with CF53 and V2A shafts. In pivoting application, the hard-chromed shaft proves to be the ideal partner.
Please contact us in case the shaft material scheduled by you is not included here.

Shaft materials

Fig. 07: Wear in swivelling and oscillating applications at constant load with various shaft materials, p = 2 MPa

X = Load [MPa]
Y = Wear [μm/km]

A = Cf53
B = hard chrome-plated
C = V2A
D = St37

pink = rotating
blue = oscillating

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

+ resistant 0 conditionally resistant - non-resistant

Table 05: Chemical resistance of iglidur® R

Electrical properties

Specific forward resistance	> 10¹² Ωcm
Surface resistance	> 10¹² Ω

Chemical resistance

iglidur® R bearings can be used under various environmental conditions and in contact with numerous chemicals. Table 05 gives an overview of the chemical resistance of iglidur® R bearings at room temperature.

Radioactive rays

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

UV-resistant

iglidur® R bearings are resistant to UV radiation, but the tribological properties deteriorate with continuous exposure.

Vacuum

In vacuum, iglidur® R degases. The use in vacuum is possible only limitedly.

Electrical properties

iglidur® R bearings are electrically insulating.

Maximum moisture absorption
At +23 °C / 50% r.h.	0,2 % weight
Max. water absorption	1.1 % weight

Table 06: Moisture absorption of iglidur® R

Moisture absorption

The moisture absorption of iglidur® R plain bearings is approximately 0.2 % in standard atmosphere. The saturation limit submerged in water is 1.1 %. This must be taken into account for these types of applications.

Diagram 10: Effect of moisture absorption

X = Moisture absorption [weight %]
Y = Reduction of inside diameter [%]

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® R 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 iglidur® R bearings according to ISO 3547-1 after the press-fit.

Installation tolerances

iglidur® R 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. In certain dimensions the tolerance in dependence on the wall thickness deviates from this (See delivery program )