Noun
52100 (uncountable)
(US, metallurgy) A common ball bearing metal, also used for blademaking, knifemaking. A high-carbon low-alloy chromium steel; typically containing 1.0% carbon and 1.5% chromium, with low silicon (0.25%) and manganese (0.35%).
52100 bearings developed the largest compressive residual stress
52100 continues to be the most used bearing steel
In the annealed condition 52100 is comparatively easy to machine
One of the first improvements was to replace the steel cubes with convert hardened 52100 alloy ball bearings. Source: Internet