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igubal® - Technical data

igubal® spherical balls made of iglidur® W300

The spherical ball of the standard spherical bearings is made of iglidur® W300, a material that distinguishes itself by the lowest coefficient of friction and extremely low stick-slip effect. The latter is particularly important in low loads and extremely slow movements.


Ductile, tough thermoplastic alloy

Very low coefficients of surface friction in dry operation

High holding times

Vibration dampening

Tough in high-frequency angular motions

Excellent wear resistance

Maintenance-free dry operation

Excellent resistance against chemicals

Suitable for rotary, oscillating and linear movements

Also suitable for soft shafts

igubal® housing made of igumid G and iguton G

The standard housing for the dimensional series E and K are made of igumid G, a highly impact-resistant, long-fiber reinforced polymer. For applications from +80°C to +200°C, the housing of the dimensional series E are made of iguton G.



Ideal friction partner for iglidur® W300 spherical balls

High mechanical stability

Shock- and impact-resistant

Resistant to corrosion

Chemical resistant

Shape stability

Temperature-resistant up to +200 °C

X = temperature [ºC]
Y = tensile strength in percentage [%]

Figure 02: Influence of temperature on the maximum tensile strength of igubal® rod end bearings

igubal® Operating temperature
  standard HT-Version
Lower -30 °C -40 °C
Upper, long-term +80 °C +200 °C
Upper, short-term +120 °C +240 °C
Table 02: Temperature limits for igubal® bearing elements
Screw thread designation Pitch [mm]
M 2 0,40
M 3 0,50
M 4 0,70
M 5 0,80
M 6 1,00
M 8 1,25
M 10 1,50
M 10 F 1,25
M 12 1,75
M 12 F 1,25
M 14 2,00
M 16 2,00
M 16 F 1,50
M 18 1,50
M 20 1,50
M 20 2,50
M 22 1,50
M 24 2,00
M 27 2,00
M 30 2,00
Table 03: Thread pitches of the igubal® rod end bearings
Medium Resistance
  standard HT-Version
Alcohols + to 0 +
Hydrocarbons + +
Fats, oils, without additives + +
Fuels + +
Diluted acids 0 to - + to 0
Strong acids - + to -
Diluted bases + +
Strong bases 0 +
+ resistant   0 conditionally resistant   - non-resistant
All specifications at room temperature [20°C]

Table 04: Chemical resistance of igubal® bearing elements
Nominal diameter [mm]
  Gage drops Gage hangs
0 to 3 x,01 x,05
> 3 to 6 x,02 x,07
> 6 to 10 x,02 x,08
> 10 to 18 x,03 x,10
> 18 to 30 x,04 x,12
> 30 to 50 x,05 x,15
Table 05: Tolerances of the inner diameter of the spherical balls
left: inadequate test tool, gage to short
right: wrong test tool, measuring slide
Tolerance testing with gage

Application area:

igubal® bearing elements can be used without problems even in harsh environments. In moist or wet environments, the bearings are corrosion resistant, and resistant to weak acids and alkalines. The operating temperature is from -40 °C to +200 °C. Resistance to dirt and dust is outstanding.
The bearings of the igubal® bearing elements can be used without any seals, even in extremely contaminated conditions. This is true for fine dust as well as coarse dirt.


Parts of metal detectable igubal® polymer bearings can be verified as foreign particle with all common parameters used in the metal detection technology and thus ensure good food.


The load carrying capacity of the maintenance-free igubal® bearing elements is very high at normal ambient temperatures. igubal® bearing elements take up high forces and at the same time weigh only a fifth of the common metallic bearing housing. The excellent dampening properties arise as the plastic material of the two-piece bearing can absorb vibrations in contrast to steel.

In the application however properties specific to plastics such as temperature dependency and creep behavior have to be considered. Therefore in particular cases the load carrying capacity of the rod end bearings should be checked in a practical trial with high constant loads, with low load speeds and at higher temperatures.

Coefficients of surface friction and speeds

An important advantage of the maintenance-free igubal® bearing elements is the fact that the fast rotary motions of the mounted shaft directly take place in the iglidur® W300 bearing ball. The advantage of this plastic/steel plain bearing is that high speeds can be achieved in dry operation. Taking the radial loads into account, maximum surface speeds up to 0.5 m/s rotating can be attained.

The angular movements of the spherical bearing in contrast take place on the spheroidal outer diameter of the bearing ball.

The maintenance-free igubal® bearing elements casually permit linear movements of the shaft.

Operation temperatures

igubal® bearing elements are used in the temperature range of -30°C to +80°C. The HT version can be used continuously at a temperature of +200°C. Table 02 shows the influence of temperature on the load capacity of the igubal® bearing elements.

Chemical resistance

Both the iglidur® W300 bearing ball and the igumid G housing are resistant against weak alkalis, weak acids as well as against fuels and all types of lubricants. The humidity absorption of igubal® amounts to about 1.3 Wt.-% in standard climatic conditions. The saturation limit in water is 6.5%. This should be considered according to environmental influences. The HT version can be used for a higher resistance to chemicals.

Radioactive rays

Self-aligning igubal® bearings are resistant up to a radiation intensity of 3 x 102 Gy.


The corrosion resistance of the igubal® bearing elements make them particularly suitable for outdoor use. igubal® bearing elements are permanently resistant against UV rays. A minor variation in the ball color (dark) through UV radiation and other atmospheric exposure do not influence the mechanical, electrical or thermal properties.


igubal® bearing elements can be used with different tolerances according to each application. They are designed with a large clearance in the standard product, which enables a secure operation even under high peripheral speeds. The bore of the inner ring has a tolerance according to E10. The shafts should have tolerances between h6 and h9. The tolerances are provided in the table. Please contact us in case you require lower or other bearing tolerances.

The terms "Apiro", "AutoChain", "CFRIP", "chainflex", "chainge", "chains for cranes", "ConProtect", "cradle-chain", "CTD", "drygear", "drylin", "dryspin", "dry-tech", "dryway", "easy chain", "e-chain", "e-chain systems", "e-ketten", "e-kettensysteme", "e-loop", "energy chain", "energy chain systems", "enjoyneering", "e-skin", "e-spool", "fixflex", "flizz", "i.Cee", "ibow", "igear", "iglidur", "igubal", "igumid", "igus", "igus improves what moves", "igus:bike", "igusGO", "igutex", "iguverse", "iguversum", "kineKIT", "kopla", "manus", "motion plastics", "motion polymers", "motionary", "plastics for longer life", "print2mold", "Rawbot", "RBTX", "readycable", "readychain", "ReBeL", "ReCyycle", "reguse", "robolink", "Rohbot", "savfe", "speedigus", "superwise", "take the dryway", "tribofilament", "triflex", "twisterchain", "when it moves, igus improves", "xirodur", "xiros" and "yes" are legally protected trademarks of the igus® GmbH/ Cologne in the Federal Republic of Germany and where applicable in some foreign countries. This is a non-exhaustive list of trademarks (e.g. pending trademark applications or registered trademarks) of igus GmbH or affiliated companies of igus in Germany, the European Union, the USA and/or other countries or jurisdictions.

igus® GmbH points out that it does not sell any products of the companies Allen Bradley, B&R, Baumüller, Beckhoff, Lahr, Control Techniques, Danaher Motion, ELAU, FAGOR, FANUC, Festo, Heidenhain, Jetter, Lenze, LinMot, LTi DRiVES, Mitsubishi, NUM,Parker, Bosch Rexroth, SEW, Siemens, Stöber and all other drive manufacturers mention on this website. The products offered by igus® are those of igus® GmbH