iglidur® N54 - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (120 MPa to +20 °C)

X = Temperature [°C]
Y = Load [MPa]

Figure 03: Deformation under load and temperatures

X = Load [MPa]
Y = Deformatio [%]

Mechanical properties

Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it. The compressive strength of iglidur® N54 bearings decreases with increasing temperatures. Fig. 02 clarifies this relationship. At the long-term permitted application temperature of 120°C, the permitted surface pressure still amounts to 10 MPa.

Figure 03 shows the elastic deformation of iglidur® N54 at radial loads.

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

Table 02: Maximum surface speeds

Permitted surface speeds

Even if the typical applications for iglidur® N54 plain bearings are more commonly for intermittent service, depending on the type of motion, the maximum attainable speeds can be quite high. The speeds stated in Table 02 are limit values for the lowest bearing loads. As loads increase, the admissible speed is reduced with higher loads due to the limitations of the pv value.

iglidur® N54	Application temperature
Lower	- 40 °C
Upper, long-term	+ 80 °C
Upper, short-term	+ 120 °C
Secure axially in addition	+ 60 °C

Table 03: Temperature limits for iglidur® N54

Temperatures

The short-term admissible temperature limit is +140 °C, thus permitting the use of iglidur® N54 plain bearings in all applications with elevated ambient temperatures. However, the compressive strength of iglidur® N54 bearings decreases as temperatures increase. The additional frictional heat in the bearing system should be taken into account when considering the temperature limits. An additional securing is recommended at temperatures higher than +60°C.

Figure 04: Coefficients of friction dependent on the surface speed, p = 1 MPa

X = Sliding 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

iglidur® N54 has a low coefficient of friction. However it must be noted that a gliding partner with a rough surface finish increases the friction. We recommend shaft surface finishes (Ra) of 0.1 to a maximum of 0.4 µm.
 
The coefficient of friction of iglidur® N54 bearings is only marginally dependent on the surface speed.
 
The influence of the load is greater; an increase in load lowers the coefficient of friction up to 0.8.

iglidur® N54	Dry	Grease	Oil	Water
Coefficients of friction µ	0,15 - 0,23	0,09	0,04	0,04

Table 04: Coefficients of friction for iglidur® N54 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

It is important to select a suitable shaft material. As a rule, iglidur® N54 is better suited for hard or soft shafts, but "hard" shaft surfaces tend to have better holding times. Starting at loads of 1 MPa, wear increases measurably and continuously.

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

+ resistant      0 limited resistance      - not resistant
All specifications at room temperature[+20 °C]
Table 05: Chemical resistance of the iglidur® bearings N54

Electrical properties

Specific forward resistance	< 1013 Ωcm
Surface resistance	< 1011 Ω

chemical resistance

iglidur® N54 plain bearings have good resistance to chemicals. They are resistant to most lubricants. iglidur® N54 is not impaired by most weak organic and inorganic acids and bases.

Radioactive rays

iglidur® N54 plain bearings can be used with restrictions when exposed to radiation. They are resistant up to a radiation intensity of 1 x 10⁴ Gy.

UV-resistant

iglidur® N54 plain bearings are resistant to UV rays.

Vacuum

The low water elements degas in the vacuum. Applications under vacuum conditions are possible with restrictions.

Electrical properties

iglidur® N54 plain bearings are electrically insulating.

Maximum moisture absorption
by +23 °C/50 % r. F.	1,6 weight-%
Max. water absorption	3,6 weight-%

Table 06: humidity absorption of iglidur® N54

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

humidity absorption

The moisture absorption of iglidur® N54 bearings is about 1.6% in standard climatic conditions. The saturation limit in water is 3.6 %.

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® N54 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

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

Installation tolerances

iglidur® UW 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 )