| Heat Resistant Iron | HE | HR | HS | HSV |
| Tensile Strength (psi) | 25000 | 40000 | 60-100,000 | 100-120,000 |
| Hardness (BHN) | 160-180 | 300+ | 170-210 | 170-210 |
| Caracteristics | Gray Iron | White Iron | Ductile Iron | Ductile Iron |
| Applications | Cyclic | 1350 F Cyclic | 1800 F Cyclic | 1600 F Continuous |
| ASTM Equivalent | A319 class 1 | A319 class 3 type D |