iglidur® H370 - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (75 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® H370 bearings decreases. Fig. 02 clarifies this connection.
 
Figure 03 shows how iglidur® H370 elastically deforms under radial load. Under the maximum recommended surface pressure of 75 MPa, the deformation at room temperature is below 2.5%.

m/s	Rotary	oscillating	Linear
Constant	1,2	0,8	4
Short-term	1,5	1,1	5

Table 02: Maximum surface speeds

Permitted surface speeds

The maximum permitted surface speed is dependent on whether the temperature in the bearing location rises strongly or not. iglidur® H370 is suitable for surface speeds up to 1.2 m/s (rotating) and 4 m/s (linear) respectively.

The maximum values stated in Table 02 are valid only with minimum pressure loads and are often not attained in practice.

iglidur® H370	Operating temperature
Lower	- 40 °C
Upper, long-term	+ 200 °C
Upper, short-term	+ 240 °C
Secure axially in addition	+ 100 °C

Table 03: Temperature limits for iglidur® H370

Temperatures

With increasing temperatures, the compressive strength of iglidur® H370 bearings decreases. 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 +100°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 coefficient of friction alters only little, like the wear resistance with increasing load and surface speed (Fig 04 and 05).

iglidur® H370	Dry	Grease	Oil	Water
Coefficients of friction µ	0,07 - 0,17	0,09	0,04	0,04

Table 04: Coefficients of friction for iglidur® H370 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

The Fig. 06 and 07 display the results of tests with different shaft materials conducted with plain bearings made of iglidur® H370.
 
For loads up to 2 MPa, the hard-chromed shaft is the best counter partner for the iglidur® H370 bearings in rotating applications. The high coefficients of wear with V2A shafts are striking, which are prone to the stick-slip effect due to their extremely smooth surfaces. The St37 shaft shows better values than Cf53, despite the same values in the lowest range, from 2 MPa. On the other hand, the V2A shaft shows a clear advantage in swivelling movements.

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

+ resistant     0 conditionally resistant     - non-resistant
All specifications at room temperature [+20°C]
Table 05: Chemical resistance of iglidur® H370

Electrical properties

Specific forward resistance	< 105 Ωcm
Surface resistance	< 105 Ω

iglidur® H370 bearings are electrically insulating.

Chemical resistance

iglidur® H370 bearings have a good resistance against chemicals. They are resistant to most lubricants.

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

Radioactive rays

H370 withstands both the neutron and gamma particle radiations without noticeable loss to its excellent mechanical properties. iglidur® H370 bearings are radiation resistant up to a radioactive intensity of 2 x 10² Gy.

UV-resistant

iglidur® H370 bearings are permanently resistant against UV rays.

Vacuum

Water elements are degassed in the vacuum. Due to the low water absorption, an application in the vacuum is however possible.

Maximum moisture absorption
by +23 °C/50 % r. F.	< 0,1 weight-%
Max. water absorption	< 0,1 weight-%

Table 06: The moisture absorption of iglidur® H370 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® H370 bearings is about 0,1% in standard climatic conditions. The saturation limit in water is likewise below 0.1%. iglidur® H370 is also therefore the best suited bearing material for underwater applications.

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® H370 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 for iglidur® H370 bearings according to ISO 3547-1 after the press-fit.

Installation tolerances

iglidur® H370- 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. In certain dimensions the tolerance in dependence on the wall thickness deviates from this (See delivery program )