| 项目 | N-1 | N-2a | N-2b | N-3a | N-3b | N-4 | N-5 | N-6 | |
| 耐火度, ℃ ≥ | 1750 | 1730 | 1730 | 1710 | 1710 | 1690 | 1670 | 1580 | |
| 荷重软化开始温度, ℃, [0.2MPa×0.6%] ≥ | 1400 | 1350 | — | 1320 | — | 1300 | — | — | |
| 重烧线变化率， % | 1400℃×2h | +0.1 -0.4 | +0.1 -0.5 | +0.2 -0.5 | — | — | — | — | — |
| 1350℃×2h | — | — | — | +0.2 -0.5 | +0.2 -0.5 | +0.2 -0.5 | +0.2 -0.5 | — | |
| 显气孔率, % ≤ | 22 | 26 | 24 | 24 | 26 | 24 | 26 | 28 | |
| 常温耐压强度, MPa ≥ | 30.0 | 20.0 | 25.0 | 20.0 | 15.0 | 20.0 | 15.0 | 15.0 | |
