Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon and other nonmetals to obtain other desired properties. Stainless steel's resistance to corrosion results from the chromium, which forms a passive film that can protect the material and self-heal in the presence of oxygen.

The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products.

The biological cleanability of stainless steel is superior to both aluminium and copper, and comparable to glass. Its cleanability, strength, and corrosion resistance have prompted the use of stainless steel in pharmaceutical and food processing plants.

Different types of stainless steel are labeled with an AISI three-digit number.The ISO 15510 standard lists the chemical compositions of stainless steels of the specifications in existing ISO, ASTM, EN, JIS, and GB standards in a useful interchange table.

Hardness

Stainless steel is a highly durable metal known for its impressive hardness. This quality is primarily due to the presence of two key components: chromium and nickel. Chromium forms an oxide layer on the metal's surface, protecting it from corrosion and wear. Meanwhile, nickel contributes to the metal's strength and ductility, enhancing its overall hardness. Stainless steel can also be hardened through heat treatment processes such as annealing or quenching, further improving its hardness.

Thermal Conduction

The thermal conductivity of stainless steel depends on its composition and structure. Typically, stainless steel has a thermal conductivity ranging from 15 to 20 W/mK (watts per meter Kelvin). Due to this, it keeps more energy that stabilizes the surrounding temperature.

Density

The density of stainless steel can be somewhere between 7,500kg/m3 to 8,000kg/m3 depending on the alloy.