Chemical composition: C Si Mn S P Chilled shot(grit) 2.20-3.60 ≤2.20 ≤0.50 ≤0.25 ≤0.200 Decarburized casting shot 2.20-3.60 ≤2.20 ≤0.50 ≤0.25 ≤0.200 Cast steel shot(grit) 0.85-0.12 ≥0.40 0.60-1.20 ≤0.05 ≤0.050 Technical index: Chilled shot(grit) Decarburized casting shot Cast steel shot(grit) Hardness: 55-64 25-30 40-45