| Imperial: |
| TFe≥94% MFe≥90% η＞96% SiO2＜2% |
| SiO2：2～3.5% S＜0.03% P＜0.03% C＜0.04% |
| Stair: |
| TFe：92～94% MFe：86～90% η：94～96% |
| SiO2：2～3.5% S＜0.03% P＜0.03% C＜0.04% |
| Two class: |
| TFe:90～92% MFe：83～86% η：92～94% |
| SiO2：3.5～5% S＜0.05% P＜0.05% C＜0.07% |
| Third class: |
| TFe：88～90% MFe：80～83% η：90～92% |
| SiO2：5～6.5% S＜0.07% P＜0.07% C＜0.1% |
| Eligibility: |
| TFe：86～88% MFe：76～80% η：89～90% |
| SiO2：6.5～8% S＜0.1% P＜0.1% C＜0.3% |
