Bearing steel is the general term for alloy steel used to manufacture various rolling bearing rings and rolling elements. Bearing steel is divided into four categories: high-carbon chromium bearing steel, carburized bearing steel, high-carbon chromium stainless bearing steel and high-temperature bearing steel.
Examples of grades：High chromium bearing steel (GCr6、GCr9、GCr9SiMn、GCr15、GCr15SiMn)；Chromium-free bearing steel (GSiMnV、GSiMnVXt、GSiMnMoV、GSiMnMoVXt、GMnM oV、GMnMoVXt)；Carburized bearing steel (G20CrMo、G20CrNiMo、G20CrNi2Mo、G20Cr2Ni4、G10CrNi3Mo、G20Cr2Mn2Mo)；Stainless steel bearing (9Cr18、9Cr18Mo)；High temperature bearing steel (Cr4Mo4V、H10Cr4Mo4Ni4V、W9Cr4V2Mo、2W10Cr3NiV、W18Cr4V).
Except for stainless bearing steel and high-temperature bearing steel, G is added to the bearing steel grade head to indicate structural steel. High chromium bearing steel and chromium-free bearing steel do not indicate the carbon content, and the Cr content is indicated in thousandths. In carburized bearing steel, the carbon content is generally indicated in ten thousand fractions. For example, in G20CrMo, G means structural steel, 20 means carbon content is about 20‱, and other main alloying elements have higher content of chromium and molybdenum. Stainless steel bearing steel is represented by stainless steel grades; for example, in 9Cr18, 9 means that the carbon content is 9‰ and the chromium content is 19%. High-temperature bearing steel adopts the designation method of heat-resistant steel; for example, in W9Cr4V2Mo, the content of tungsten is 9%, the content of chromium is 4%, the content of vanadium is 2%, and the content of molybdenum is relatively high.