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iglide® UW - Material data

Materials table

General features Unit iglide® UW Test method
Density g/cm³ 1.52
Color Black
Max. moisture absorption at 73° F/50% R. H. Wt.-% 0.2 DIN 53495
Max. moisture absorption Wt.-% 0.8
Coefficient of friction, dynamic against steel µ 0.15 - 0.35
p x v value, max. (dry) psi x fpm 2,800

Mechanical properties
Modulus of elasticity psi 1,392,000 DIN 53457
Tensile strength at 68° F psi 13,050 DIN 53452
Compressive strenght psi 10,150
Permissible static surface pressure (68° F) psi 5,802
Shore D hardness 78 DIN 53505

Physical and thermal properties
Upper long-term application temperature °F 194
Upper short-term application temperature °F 230
Lower application temperature °F -58
Thermal conductivity [W/m x K] 0.60 ASTM C 177
Coefficient of thermal expansion (at 73° F) [K-1 x 10-5 ] 6 DIN 53752

Electrical properties
Specific volume resistance Ωcm < 10 5 DIN IEC 93
Surface resistance Ω < 10 5 DIN 53482


Permitted p x v values

For iglide® UW plastic bushings with 0.039 inches wall thickness in dry operation against a steel shaft, at 68° F, installed in a steel housing.

iglide® UW was developed for underwater applications in which the maximum temperatures clearly lie below 212° F. For application temperatures above this limit, the bushings made of iglide® UW500 are available. Though iglide® UW was developed for application in liquids, it is also suitable for dry operation. This one is particularly important in applications that call for both dry and wet operations. These applications can be seen often in practice. The features of the bushings made of iglide® UW described in this section apply to the dry operation. Unless it is expressly mentioned otherwise.


Deformation under load and temperatures Deformation under load and temperatures

Compressive Strength

The graph shows the maximum recommended surface pressure for various temperatures. iglide® UW plastic bushings are suitable for application under low to medium loads. High loads occur rather seldom in underwater applications.

The wear increases from a radial load of 725 psi upward.


Maximum surface speed

fpm Rotating Oscillating Linear
Constant 98 78 393
Short-term 295 216 590

Permitted surface speeds

iglide® UW is excellent in both dry and wet operations. Through a hydrodynamic lubrication, attained under water with high speeds, surface speeds far above 393 fpm can be achieved.

In dry operation the iglide® UW plastic bushings can be used anyhow up to 295 fpm on the short term.


Maximum recommended surface pressure dependent on the temperature Maximum recommended surface pressure dependent on the temperature

Temperatures

As mentioned earlier, the iglide® UW plastic bushings are recommended rather for the low temperature range. Frictional heat should be taken into account in the dry operation from a maximum 194° F temperature at the bushing position.

In underwater application the medium serves to put down the heat, which temperature is primarily important.

Temperature limits

iglide® UW Application temperature
Lower - 58 °F
Upper, long-term + 194 °F
Upper, short-term + 230 °F
Additional axial securing + 176 °F


Coefficients of friction dependent on the surface speed Coefficients of friction dependent on the surface speed, p =108 psi

Friction and wear

In underwater application the coefficients of friction are, as is known, essentially lower than in dry operation through the lubrication. In dry operation the coefficient of friction rises up to 0.4 with low loads. With higher loads, it lowers to 0.1.

The surface finishes of the shafts should not be extremely smooth in order to prevent a high adhesion effect and the entailing increases in the coefficient of friction.

Please contact us for the specifications of shaft surface finishes in underwater applications.

Coefficients of friction for iglide® UW against steel
(Shaft finish = 40 rms, 50 HRC)

iglide® UW Dry Grease Oil Water
Coefficients of friction µ 0.15 - 0.35 0.09 0.04 0.04

Coefficients of friction dependent on the load Coefficients of friction dependent on the load, v = 1.96 fpm
Coefficients of friction dependent on the shaft surface Coefficients of friction dependent on the shaft surface (1050 hard chromed and ground steel)

Wear with different shaft materials, oscillating and rotating movement Wear, rotating application with different shaft materials, load p = 108 psi, v = 98 fpm

Shaft materials

With low loads in rotary motion, the influence of the shaft materials given in the graph on the iglide® UW plastic bushings is relatively low. The graph shows that this strongly varies with increasing loads.

Call your igus® consultant for queries on a special counter partner.

Wear with various shaft materials in the rotating operation Wear with various shaft materials in the rotating operation dependent on the pressure
Wear with different shaft materials, oscillating and rotating movement Wear with pivoting and rotating applications with shaft material 1050 hard chromed and ground steel, dependent on the pressure

Important tolerances for iglide® UW plastic bushings according to ISO 3547-1 after the press-fit.

Diameter
d1 [inch]
Shaft h9
[inch]
iglide® UW
E10 [inch]
Up to 0.019685 0 - 0.0009843 +0.000551 + 0.0021260
> 0.1181 to 0.2362 0 - 0.0011811 +0.000787 + 0.0026771
> 0.2362 to 0.3937 0 - 0.0014173 +0.000984 + 0.0032677
> 0.3937 to 0.7087 0 - 0.0016929 +0.001260 + 0.0040157
> 0.7087 to 1.1811 0 - 0.0020472 +0.001575 + 0.0048819
> 1.1811 to 1.9685 0 - 0.0024409 +0.001969 + 0.0059055

Installation tolerances

iglide® UW plastic bushings are standard bushings for shafts with h-tolerance (recommended minimum h9).

After the installation in a housing bore with H7 tolerance, the inner diameter of the bushing automatically adjusts to the E10 tolerance.


Medium Resistance
Alcohol + to 0
Hydrocarbons, chlorinated +
Greases, oils, without additives +
Fuels +
Weak acids 0 to -
Strong acids -
Weak alkaline +
Weak alkaline + to 0
+ resistant      0 conditionally resistant      - non-resistant

Influence of moisture absorption Influence of moisture absorption of iglide® UW plastic bushings


Electrical properties

Specific volume resistance > 105 Ωcm
Surface resistance > 105 Ω

Chemical resistance

iglide® UW plastic bushings are resistant to diluted alkaline and very weak acids as well as to solvents and all kinds of lubricants.

The humidity absorption of iglide® UW plastic bushings amounts to about 0.2% in standard climatic conditions. The saturation limit in water is 0.8%. These values are so low that a moisture expansion need to be considered only in extreme cases.

Radioactive rays

iglide® UW plastic bushings are radiation resistant up to a radioactive intensity of 3 x 10² Gy.

UV-resistant

iglide® UW plastic bushings are resistant to the influence of UV rays.

Vacuum

The use in vacuum is possible only conditionally. Only dry plastic bushing made of iglide® UW should be tested in vacuum.

Electrical properties

Plastic bushings made of iglide® UW are electrically conductive.