iglidur® L350 – material data

Material data table

General specificationsUnitiglidur® L350Testing method
Densityg/cm³1,54 
Colour dark grey 
Max. moisture absorption at 23 °C/50% r.h.% weight0,4DIN 53495
Max. total moisture absorption% weight1,4 
Coefficient of sliding friction, dynamic, against steelµ0,07 – 0,18 
pv value, max. (dry)MPa x m/s3,00 

Mechanical properties
Flexural modulusMPa15.882DIN 53457
Flexural strength at +20°CMPa210DIN 53452
Compressive strengthMPa210 
Recommended max. surface pressure (20°C)MPa59 
Shore-D hardness 80DIN 53505

Physical and thermal properties
Max. long-term application temperature°C+180 
Max. short-term application temperature°C+210 
Min. application temperature°C-100 
Thermal conductivity[W/m x K]0,61ASTM C 177
Coefficient of thermal expansion (at 23 °C)[K-1 x 10-5]7DIN 53752

Electrical properties
Specific volume resistanceΩcm> 105DIN IEC 93
Surface resistanceΩ> 105DIN 53482

Table 01: Materials table iglidur® L350

Diagram 01: Permissible pv values for iglidur® L350 Diagram 01: Permissible pv values for iglidur® L350

pv-values of iglidur® L350

With iglidur L350, another lubrication and maintenance-free material is now available, which is designed for continuous high speeds. Due to the low thermal expansion and low moisture absorption, bearings can be manufactured with minimal potential to expand. iglidur® L350 is especially suitable for use in fans, blowers or electric motors – and the costs are also lower.
 
Diagram 01: Permissible pv values for iglidur® L350 plain bearings with a wall thickness of 1 mm in dry operation against a steel shaft, at +20°C, mounted in a steel housing 
 
X = Surface speed [m/s], Y = Load [MPa] 

MediumResistance
Alcohol+
Hydrocarbons+ up to 0
Greases, oils without additives+
Fuels+
Diluted acids+
Strong acids+
Diluted alkalines+
Strong alkalines+
Table 02: Material resistance of iglidur® L350 at room temperature [+20°C]
+ resistant      0 limited resistance      - non-resistant
 

Electrical properties

Specific volume resistance> 105 Ωcm
Surface resistance> 105 Ω
Table 03: Electrical properties of iglidur® L350

Moisture absorption

The very low moisture absorption of 0.4 %weight in standard climatic conditions and 1.4 %weight at maximum water absorption also enables continuous operation in high humidity or in liquid media.

Vacuum

In vacuum, the moisture content is released as vapour. Due to its low moisture absorption, use in a vacuum is possible.

Radiation resistance

Plain bearings made from iglidur® L350 are resistant up to a radiation intensity of 2 x 10² Gy. Higher radiation affects the material and may result in a significant decrease in mechanical properties.

UV resistance

The material properties of iglidur® L350 plain bearings do not change under UV rays or other weathering effects.

Mechanical properties

With increasing temperatures, the compressive strength of iglidur® L350 plain bearings decreases. The diagram 02 shows this inverse relationship. The recommended maximum surface pressure is a mechanical material parameter. No conclusions regarding the tribological properties can be drawn from this.

Maximum recommended surface pressure as a function of temperature (59 MPa at +20°C) Diagram 02: Recommended maximum surface pressure of a function of temperature (59 MPa at +20 °C)
 
X = Temperature [°C], Y = Load [MPa]

Deformation under load and temperature

Diagram 03 shows the elastic deformation of iglidur® L350 under different loads. At the recommended maximum surface pressure of 59 MPa the deformation is less than 2,5 % at room temperature. A plastic deformation can be negligible up to this value. It is however also dependent on the duty cycle of the load.
Deformation under load and temperatures Diagram 03: Deformation under pressure and temperature
 
X = Load [MPa], Y = Deformation [%]

Maximum running speed

m/sRotatingOscillatinglinear
Continuous3,01,54,0
Short-term4,03,06,0
Table 04: Max. surface speed of iglidur® L350

Permissible surface speeds

iglidur® L350 has been developed especially for high surface speeds
with low loads. Due to the high
temperature resistance of iglidur® L350, the physical
limit of the bearing has been,
increased significantly. In addition, the extremely
low wear allows long sliding distances to be attained quickly
in the case of high peripheral speeds. The maximum
speeds are shown in adjacent table.

iglidur® L350Application temperature
Minimum- 100 °C
Max. long-term+ 180 °C
Maximum, short-term+ 210 °C
In addition secure axially from+ 140 °C
Table 05: Temperature limits for iglidur® L350

Temperatures

The iglidur® L350 plain bearings can be used in temperatures up to +210°C for the short-term. Note that a mechanical securing of the bearing is recommended from temperatures of +140°C. Higher temperatures can also cause the bearing to lose its press-fit seating and move in the hole.

Coefficients of friction depending on the speed Diagram 04: Coefficient of friction as a function of the surface speed, p = 0,75MPa
 
X = Surface speed [m/s] Y = Coefficient of friction μ

Friction and wear

The very low coefficient of friction remains, even at high speeds. Diagram 04 shows this relationship on a steel shaft at 0.75 MPa surface pressure.
iglidur® A300DryGreasesOilWater
C. o. f. µ0,07 - 0,180,060,040,03

Table 06: Coefficients of friction for iglidur® A350 against steel (Ra = 1 µm, 50 HRC)

Wear, rotating application with different shaft materials, p = 1 MPa, v = 0.3 m/s Diagram 05: Wear, rotating with different shaft materials, p = 1MPa, v = 0.3m/s
 
Y= Wear [μm/km]

Shaft materials

Diagram 05 compares the wear of a sintered bearing with that of bearings made of the materials iglidur® L500 and L350. At a surface speed of 1.5 m/s or more, the wear of the sintered bearing increases exponentially whereas the wear of the iglidur® plain bearings almost remains the same up to a speed of more than 3 m/s.
 
A = Aluminium, hard-anodised
B = Free cutting steel
C = Cf53
D = Cf53, hard-chromed
E = St37
F = V2A
G = X90
Rotary wear against Cf53, p = 0.25 MPa, T = +23°C Diagram 06: Rotating wear against Cf53, p = 0.25 MPa, T = +23°C
 
X = Surface speed, [m/s], Y = Wear rate [μm/km]
A = Sintered bearing, B = iglidur® L350, C = iglidur® L500
Rotating coefficient of friction - "High speed" against Cf53, p = 1 MPa (except for iglidur® L250), T = +23°C Diagram 07: Rotating coefficient of friction - "High speed" against Cf53, p = 1 MPa (except for iglidur® L250), T = +23°C
 
X = Surface speed [m/s], Y = Coefficient of friction [μ]
A = iglidur® L350, B = iglidur® L500

Diameter
d1 [mm]
Shaft h9
[mm]
iglidur® A350
F10 [mm]
Housing H7
[mm]
to 3+0,000 +0,010+0,006 +0,046–0,025 +0,000
> 3 to 6+0,000 +0,012+0,010 +0,058–0,030 +0,000
> 6 to 10+0,000 +0,015+0,013 +0,071–0,036 +0,000
> 10 to 18+0,000 +0,018+0,016 +0,086–0,043 +0,000
> 18 to 30+0,000 +0,021+0,020 +0,104–0,052 +0,000
> 30 to 50+0,000 +0,025+0,025 +0,125–0,062 +0,000
> 50 to 80+0,000 +0,030+0,030 +0,150–0,074 +0,000
> 80 to 120+0,000 +0,035+0,036 +0,176–0,087 +0,000
> 120 to 180 +0,000 +0,040+0,043 +0,203+0,000 +0,100
Table 07: Important tolerances for plain bearings according to ISO 3547-1 after press-fit

Installation tolerances

iglidur® L350 plain bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). The bearings are designed for press-fit into a housing machined to a H7 tolerance. After being assembled into a nominal size housing, in standard cases the inner diameter automatically adjusts to the F10 tolerances. For particular dimensions the tolerance differs depending on the wall thickness (please see product range table).