The resistance of a material to thermal fatigue is fundamentally linked to the above parameters. But comparative data on materials must be compiled in identical testing conditions, seldom encountered in use, or must take into account a combination of pure thermal resistance and other factors, such as resistance to crack propagation, presence of micro cracks caused by localized stress or deformations, or even prevalence of oxidation or growth.

The best evaluation of a material's resistance to thermal fatigue takes place when the material is in use but scattered and hard-to-interpret results are the drawback.

Experience shows that in temperature conditions nearing transformation temperatures (1325°F), when resistance to oxidation/scaling and warping are important factors for applications in which the thermal cycling does not take place with significant impact conditions, Gray iron of the type described here is the best available material. At this same temperature level, if the thermal cycling is accompanied by some impacts, ductile iron of the type described here is the best choice, whenever dimensional stability is important.