While the contact surfaces between the bearing rings and rolling elements are subjected to repeated heavy stress,they must still maintain high rotational precession, therefore,the materials used for bearings rings and rolling
elements require the following characteristics:

  • high rolling contact fatigue strength
  • high hardness
  • high wear resistance
  • high dimensional stability
  • high mechanical strength

The material used by JBC is high carbon chromium bearing steel GCrl5-GB/T18254 equivalent such as AISI 52100(USA), DIN 100Cr6 (Germany) JIS SUJ2 (Japan) and BS 534A99 (UK).

Stainless steel

JBC stainless steel bearings are made of steel type 9Cr18 which is especially corrosion resistant. Most of our bearings can be produced in this steel quality as well, even plain bearings!

Siliciumnitrid (Si3N4)

Siliciumnitrid (Si3N4) plays currently a dominating role under the nitrid ceramics. It shows a combination of excellent material qualities that cannot be reached by other ceramics up to now:

- high toughness
- high firmness, even at high temperatures
- excellent temperature change permanence
- excellent wear permanence
- low warm stretch
- middle warm conductivity
- good chemical permanence.

This quality combination provides ceramics, that may be used for the most extreme applications. Silicium nitride ceramics are predestined therefore for mechanical engineering parts with very high dynamic demands and reliability standards.

To produce dense Silicium nitride ceramic, we start with a with sinter additives (Al2O3, Y2O3, MgO etc.) complemented Submicron Si3N4 powder. This will be sintered at temperatures between from 1,750 to 1,950°C after the styling process. Caused by the decomposition of Si3N4 to (Si and N2) after approx. 1,700 °C with normal pressure of the sinter atmosphere, the N2 pressure is raised during the sintering to counteract against the decomposition.
Siliciumnitride is used as a special material in the bearing technology for hybrid bearings (rolling element from Si3N4) and full ceramic bearings (rolling element and running rings from Si3N4)

Zircon oxide (ZrO2)

Zircon oxide is an extremely resistant material. It stands temperatures well over the glaze point of aluminium and does not corrode. Moreover, it has a low thermal conductivity. At temperatures above 600°C, it is electrically conducting and is often used in oxygen-sensor cells in high temperature induction kilns.
Its qualities are:

  • the highest edge firmness
  • resistant to temperature up to 2400 °C
  • high density
  • high bending strength (tenaciously)
  • bad thermal conductivity (only 20% of aluminium)
  • chemically sluggishly
  • the highest surface quality
  • high mass (density 6.0 g / cm3)
  • high thermal expansion (like steel)
  • extremely warmth-isolating
  • electrically isolating
  • Colour: yellow, white or ivory

Aluminumoxid (Al2O3)

The most-spreaded and cheapest material for ceramic components. The raw materials for this material are on hand in enough quantity and, therefore, inexpensive. The combination of excellent qualities with the good price are responsible for the fact that aluminium oxide has a wide palette of applications.

  • high firmness
  • high bending strength
  • thermally steady
  • excellent dielectric qualities
  • deep electric constant

In comparison to steel:

  • lighter
  • bigger elasticity module
  • deeper frictional coefficient
  • deeper temperature coefficient of expansion
  • cleaner surface treatment
  • bigger hardness at high-level temperatures
  • needs no of lubrication
  • resistant to corrosion.

    Usage examples:

    Valve balls, vacuum pumps, ball bearings, precision calibration, insulators, switch balls, and more.