These steels are used as rolling elements in bearings in all areas of mechanical engineering. In addition to Carbon, Chromium is the main alloying element. Hardness, wear resistance and fatigue strength are achieved by hardening and tempering to hardness values of over 60 HRC and special steel purity. For special bearings high-speed steels are also used.
Rolling bearings must work reliably and for a long time under high loads.
The main properties are hardness, wear resistance and high fatigue strength. These requirements are achieved by harmonised composition and hardening and tempering to hardness values above 60 HRC. For applications that require the highest resistance to rolling contact fatigue, high purity and homogeneity of the materials is required. This is usually ensured by using special metallurgical manufacturing processes, e.g. secondary metallurgical treatments or remelting processes.
In addition to carbon, conventional bearing steels usually contain alloying elements such as chromium, manganese or nickel. Modified, through-hardening high-speed steels (M50) and special case-hardened steel alloys (M50NIL) are also used for highly stressed bearings with higher operating temperatures, e.g. in the aviation industry.
Rolling bearing steels are used for rolling elements such as balls, rollers, needles and axles and spindles, mainly in the automotive, aerospace and mechanical engineering industries.