... pre-hardened 3.round bar 4.black surface 52100 BEARING STEEL Product Description Bearing Steel GCr15/52100/100Cr6 1. Material: AISI E52100 ... 2. Chemical component of bearing steel( % for reference only): C: 0.95-1.10; Si ... .025; Cr: 1.30-1.60 3. Grade name of bearing steel: G5, G10, 4. Diameter 2.0mm, 2.381mm, 3 ...