Stainless Steel 321H is an austenitic stainless steel, often called a "superaustenitic" grade. It has excellent corrosion resistance due to its high content of chromium, nickel and molybdenum, along with additions of titanium and aluminium for enhanced strength at elevated temperatures. Its composition includes 18% chromium, 9% nickel, 3% molybdenum and 0.4-0.7% titanium for enhanced creep strength properties at elevated temperatures up to 1000 degrees Celsius.

Stainless Steel 321H is a heat-resistant, austenitic chromium-nickel steel with excellent corrosion resistance. Its properties include high-temperature strength and creep resistance up to 870°C (1600°F), superior oxidation resistance, good formability, and weldability. It is commonly used in applications requiring high temperatures, such as aircraft exhaust systems, refinery equipment, power plant components, etc. Additionally, it provides an aesthetically pleasing finish that can be used in decorative designs for architecture or industrial structures.