100C6: standard material for bearing application. Steel can be through hardened or induction hardened. Heat treatment can be tuned according to different bearing operating temperature.
100C6 VAR (Vacuum Arc Re-melted): a special Aerospace specification provides extremely clean structure, resulting in superior rolling contact fatigue and bearing life.
M50: tool steel, with high hardness (>63HRc) and temperature resistance (tempering >450C°). These features result in extremely high resistance to load, wear, and temperature.
Nitrogen steel: this family of steel provide temperature resistance (tempering >450C°), fine structure for long contact fatigue and corrosion resistance.
Other materials are available for case hardening, e.g. when the bearing application requires specific structural toughness.
Aluminum Alloys: used for machined cages, this material provides a low weight solution, when high temperature and loads require a more robust design.
Titanium Alloys: SKF developed bearing cages machined from this material, providing low weight and high temperature resistance properties together with high component strength, for high acceleration applications, where the bearing cage is subject to high shock loads by the rolling elements. This solution is used in critical gearbox applications, to replace polymer or steel materials.
Polymers are normally used in cage manufacturing. SKF offers include
PA66: Standard material, used in wide application conditions and standard bearings
PA46: higher temperature range and ageing time compared to PA66
PEEK: for superior mechanical and temperature performances. Depending on application, the material can be loaded with different quantities of reinforcement materials as carbon or glass fibers, PTFE, graphite, to tune specific characteristic such as strength, elongation, thermal expansion, friction and operating temperature.
SKF can provide an extensive range of standard or customized polymer bearings, where all or some components can be manufactured using highly engineered polymers, to achieve specific product performances, as low weight or corrosion resistance and compatibility to fuels and other chemicals.
The use of Silicon Nitride as ceramic material for rolling elements (hybrid bearings) provides excellent performance for friction and weight reduction. Moreover, stiffness, high speed, acceleration capabilities, grease life, reduced lubrication needs, anti corrosion, electric insulation, longer bearing life, are among the performances enhanced by the use of this material. SKF can supply ball and roller bearings with ceramic rolling elements. Silicon Nitride rolling elements can be used in almost every application; they are very common on wheel bearing and gearbox.