1.High chrome cast ballsSize: 20mm-120mmHardness:HRC58-65; Chrome content:11-20%Chemical elements?C 1.7~3.0% Mn?2.5% Si?1.0% Mo?1.5% P?0.1% S?0.08%2.Low chrome cast ballsSize: 20mm-120mmHardness:HRC45-55; Chrome content:1-3.5%Chemical elements?C 20.~3.3% Mn?1.5% Si?1.2% Mo?1.0% P?0.15% S?0.10%3.Chrome steel cylpebs chrome content as per buyer's requirements