AISI 304 vs AISI 316 – How to Choose the Right Stainless Steel

AISI 304 and AISI 316 are the two most widely used stainless steel grades. Both are strong, corrosion-resistant and suitable for many industrial, architectural and food-related applications. The right choice depends mainly on the environment.

What is AISI 304?

AISI 304 is the standard stainless steel grade. It contains approximately 18% chromium and 8-10% nickel and offers good corrosion resistance in normal indoor and outdoor conditions. It is widely used for handrails, frames, kitchen equipment, furniture, decorative structures and general industrial parts.

What is AISI 316?

AISI 316 contains approximately 2-3% molybdenum in addition to chromium and nickel. This improves resistance to chlorides, salt and acidic environments. It is recommended for marine environments, coastal areas, swimming pools, chemical processing and demanding outdoor applications.

AISI 304 vs AISI 316 comparison table

304 vs 316 in practice

In dry indoor environments, AISI 304 is usually sufficient. In coastal or chloride-rich environments, AISI 316 provides a much longer service life and reduces the risk of pitting corrosion. The price of 316 is higher, but the added cost is often small compared with future maintenance or replacement.

Corrosion resistance

AISI 304 performs well in normal indoor and outdoor conditions. However, it can develop surface staining or pitting in chloride-rich environments. AISI 316 resists these conditions significantly better, although it is not completely maintenance-free. Regular cleaning is still important in coastal and industrial areas.

Where to use each grade

Use AISI 304 indoors, in dry environments, standard handrails, furniture, frames and general stainless steel structures. Use AISI 316 near the sea, in swimming pools, chemical plants, food processing with chlorides, and any location exposed to salt or acids.

Is 316 always better?

Not always. If the environment is mild, 304 is a cost-effective and reliable choice. 316 should be selected when the environment justifies the improved corrosion resistance.

Magnetism

Austenitic stainless steels such as 304 and 316 are generally non-magnetic in their annealed state, but cold working can make the surface slightly magnetic. Magnetism is not a reliable way to identify the grade.

Kominox supplies both AISI 304 and AISI 316 stainless steel products and can help select the correct grade for the environment, finish and application.