iglidur® RW370 – material data

Technical data

General specification

Unit

iglidur® RW370

Test method

density

g/cm³

1,34

DIN EN ISO 1183-1

Colour

beige

max. Moisture absorption at 23°C/50% room humidity.

% by weight

0,25

ISO 175

max. total moisture absorption

wt.-%

1,2

ISO 62

coefficient of friction, dynamic, against steel

0,13 - 0,17

pv value, max. (dry)

MPa - m/s

1,20

Mechanical specification

flexural modulus

MPa

2.997

DIN EN ISO 178

flexural strength at +20°C

MPa

100

DIN EN ISO 178

Compressive strength

MPa

129

max. recommended surface pressure (+20°C)

MPa

Shore D hardness

DIN 53505

Physical and thermal specification

Upper application temperature long-term

°C

+170

Upper application temperature short-term

°C

+190

Lower application temperature

°C

-50

thermal conductivity

[W/m · K]

0,22

ASTM C 177

coefficient of thermal expansion (at +23°C)

[K-1 · 10-5]

DIN 53752

Electrical specification

Volume resistivity

Ωcm

> 1012

DIN IEC 93

surface resistance

> 1012

DIN 53482

Table 01: Material properties

Download data sheet

Diagram 01: Permitted pv values for iglidur® RW370

iglidur® RW370 was specially developed for the high fire protection requirements in railway technology. It therefore fulfils the requirements of DIN EN 45545. iglidur® RW370 bearings are used in railway technology primarily in door systems, seat adjusters and joints, as well as hinges.

Mechanical specification
The compressive strength of iglidur® RW370 plain bearings decreases with increasing temperatures. diagram. 02 illustrates this relationship. The maximum recommended surface pressure represents a mechanical material parameter. Conclusions about the tribology cannot be drawn from this.

Diagram 03 shows the elastic deformation of iglidur® RW370 under different loads. A possible deformation could be, among others, dependant on the duty cycle of the load.

Maximum surface speed

m/s

rotating

oscillating

linear

long-term

0,9

0,6

2,5

short-term

1,0

0,8

2,6

Table 02: Maximum surface speed

Permissible sliding speeds
Even if the typical areas of application for iglidur® RW370 plain bearings tend to be in intermittent operation, the maximum achievable speeds are still considerable, depending on the type of movement. The speeds given in Table 03 are limit values for the lowest bearing loads. At higher loads, the permissible speed decreases with the load due to the limitations imposed by the pv value.

iglidur® RW370

Application temperature

below

-50°C

upper, long-term

+170°C

upper, short-term

+190°C

additional axial protection from

+120°C

Table 03: Temperature limits

Temperature
The maximum permissible short-term temperature is +190 °C, which means that iglidur® RW370 plain bearings can also be used in all applications with increased ambient temperatures. The compressive strength of iglidur® RW370 plain bearings decreases with increasing temperatures. When considering temperature, the additional frictional heat in the bearing system must be taken into account. At temperatures above +120 °C, additional protection is required.

Friction and wear
The very good coefficient of friction of iglidur® RW370 in dry running drops even further with speed up to a value of 1.1 m/s. Diagram 04 shows this correlation on a steel shaft. From a speed of 1.25 m/s, however, the coefficient of friction rises sharply, as the load limit of the material is reached here.

Shaft materials
Diagrams 05 and 06 show an extension of the results of tests with different shaft materials, which were carried out with plain bearings made from iglidur® RW370. At 0.3 m/s and 1 MPa surface pressure, shafts made of hard anodised aluminium and hard chrome-plated Cf53 are the most suitable sliding partners. Shafts made of 304 SS or high grade steel also deliver good results. If your intended shaft material is not included in the test results presented here, please contact us.

Shaft materials

Wear for oscillating and rotating applications with steel

Chemicals

Resistance

Alcohols

+ to 0

Hydrocarbons

Greases, oils, not additivated

Fuels

+ to 0

Diluted acids

strong acids

Dilute bases

strong bases

+ resistant 0 conditionally resistant - not resistant

All data at room temperature [+20 °C]
Table 04: chemical resistance

Moisture absorption
The moisture absorption of iglidur® RW370 bearings in a normal climate is less than 0.25% by weight. The saturation limit in water is 1.2% by weight.

Ø d1**[mm]**

housing H7**[mm]**

plain bearing F10**[mm]**

shaft h9**[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 05: Important tolerances according to ISO 3547-1 after press-fitting

Installation tolerances
iglidur® RW370 plain bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). The bearings are designed to be pressed into an H7-toleranced mounting. After installation in a mounting with nominal dimensions, the inner diameter of the bearing with F10 tolerance adjusts itself automatically. For certain dimensions, the tolerance deviates from this depending on the wall thickness (see product range).