A297 HH

Grade HH is a heat-resistant austenitic stainless steel casting alloy defined by ASTM A297/A297M, developed for high-temperature structural applications where strength and oxidation resistance are essential. It contains approximately 25% chromium and 12% nickel, offering reliable performance in oxidizing and carburizing atmospheres. HH is widely used in components such as furnace trays, supports, heat-treat baskets, and other fixtures subjected to continuous or intermittent heating cycles. Its excellent resistance to thermal fatigue and structural degradation makes it a standard material in the heat treatment, petrochemical, and metallurgical industries.