iglidur® GLW - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (80 MPa to +20 °C)

X = Temperature [°C]
Y = Load [MPa]

Fig. 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® GLW plain bearings decreases. Fig. 02 clarifies this connection.

Fig. 03 shows the elastic deformation of iglidur® GLW during radial loading. Under the maximum recommended surface pressure of 70 MPa and at room temperature, the deformation amounts to less than 3%. Under this load a plastic deformation can be negligible. However this also depends on the period of action.

Maximum surface speed

m/s	Rotary	oscillating	Linear
Constant	0,8	0,6	2,5
Short-term	1	0,7	3

Table 02: Maximum surface speeds

Permitted surface speeds

iglidur® GLW has been developed for low to medium surface speeds. In continuous operation, maximum speeds up to 0.8 m/s (rotating) and 2.5 m/s (linear) respectively are permitted. Here too, the maximum values stated in Table 02 are attained only with the minimum pressure loads and are seldom achieved in practice, as the temperature rises above the permitted maximum value.

iglidur® GLW	Operating temperature
Lower	- 40 °C
Upper, long-term	+ 100 °C
Upper, short-term	+ 160 °C
Secure axially in addition	+ 80 °C

Table 03: Temperature limits for iglidur® GLW

Temperatures

The ambient temperatures influence the properties of bearings to a high degree. Fig. 02 clarifies this connection. The bearing wear also rises with increasing temperatures in the bearing system. An additional securing is recommended at temperatures higher than +80°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

Friction and wear

The coefficient of friction μ alters like the wear resistance with increasing load (Fig. 04 and 05).

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

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

iglidur® GLW	Dry	Grease	Oil	Water
Coefficients of friction µ	0,10 - 0,24	0,09	0,04	0,04

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

Figure 06: Wear, rotating application with different shaft materials, 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

Friction and wear depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. The best suited are smoothed surfaces with an average surface finish Ra between 0.1 and 0.2 µm. (Fig. 06) The Fig. 06 displays a summary of the results of tests with different shaft materials conducted with bearings made of iglidur® GLW. Please contact us in case the shaft material scheduled by you is not included in this list.

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

+ resistant      0 conditionally resistant      - non-resistant

All specifications at room temperature [20°C] Table 05: Chemical resistance of iglidur® GLW

Electrical properties

Specific forward resistance	> 1011 Ωcm
Surface resistance	> 1011 Ω

Chemical resistance

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

Radioactive rays

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

UV-resistant

iglidur® GLW bearings are permanently resistant against UV rays.

Vacuum

In vacuum, iglidur® GLW degases. The application in vacuum should be checked earlier.

Electrical properties

iglidur® GLW bearings are electrically insulating.

Maximum moisture absorption
by +23 °C/50 % r. F.	1,3 Wt.-%
Max. water absorption	5,5 Wt.-%

Table 06: Moisture absorption

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

humidity absorption / moisture absorption

The humidity absorption of iglidur® GLW bearings amounts to about 1,3% in standard climatic conditions. The saturation limit in water is 5,5 %. This should be considered according to application conditions.

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® GLW 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 iaw. ISO 3547-1 after press-fitting.

Installation tolerances

iglidur® GLW- 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 )

Delivery program

The iglidur® GLW bearings are manufactured according to order specifications. Please contact us for applications with large numbers of bearings made of iglidur® GLW as alternative to iglidur® G.