| Brand | PN-N1 | PN-N2a | PN-N2b | PN-N3a | PN-N3b | PN-N4 | PN-N5 | PN-N6 |
| Refractoriness,
prick mark: CN
| 176 | 174 | 174 | 172 | 172 | 170 | 166 | 158 |
| Softening point under 2kgf/cm2℃;≥ | 1400 | 1350 | - | 1320 | - | 1300 | - | - |
| Reheat
linear change (%) | 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 | - |
| Apparent porosity (%);≤ | 22 | 24 | 26 | 24 | 26 | 24 | 26 | 28 |
| Cold crushing strength (MPa);≥ | 300 | 250 | 200 | 200 | 150 | 200 | 150 | 150 |
