304

304 stainless steel is an austenitic stainless steel grade in the 300 series, widely used for its corrosion resistance, formability, and weldability. It is commonly referred to as 18/8 stainless steel due to its typical chromium and nickel content.

Composition and variants

304 typically contains 18–20% chromium and 8–10.5% nickel, with carbon limited to 0.08% maximum. Other elements such as manganese, silicon, phosphorus, and sulfur are present in small amounts. Variants include 304L, which has a lower carbon content (maximum about 0.03%) to improve weldability, and 304H, which has higher carbon content (up to about 0.15%) for enhanced strength at high temperatures.

Properties

The material forms a passive chromium oxide film that provides corrosion resistance in many environments. In the annealed state it is essentially non-magnetic, though it can become slightly magnetic after cold working. It offers good formability, ductility, and toughness, along with reliable weldability and ease of fabrication. Its strength and corrosion resistance make it suitable for a range of applications, though it is not suitable for highly acidic or chloride-rich environments without protective coatings.

Applications

304 is widely used in kitchen equipment such as sinks and utensils, as well as in food processing and dairy equipment, chemical and pharmaceutical plant components, architectural trim, piping, and heat exchangers.

See also

304L and 304H variants; related stainless grades; standards including AISI 304 and UNS S30400; common welding filler for 304L.