304 vs 316 Stainless Steel for Coastal Lighting Projects

304 vs 316 Stainless Steel: Which One for Coastal lighting projects?

Short answer: For coastal and marine environments, 316 stainless steel is the safer choice. It contains molybdenum, which gives it significantly better resistance to chloride (salt) corrosion. 304 is fine for inland or low-salt areas, but near the sea, 304 will likely show rust within a few years.

Key difference: molybdenum.

• 304: 18% chromium, 8% nickel. No molybdenum.

• 316: 16-18% chromium, 10-14% nickel, 2-3% molybdenum.

Molybdenum is the key. It protects against pitting and crevice corrosion caused by chlorides.

Real-world expectation:

• 304 near the coast: rust spots in 1–3 years, depending on distance from the sea and exposure.

• 316 near the coast: 10+ years with minimal maintenance.

When to use 316:

• Beachfront hotels, villas, boardwalks

• Marinas, ports, marine parks

• Any project within 1km of the coastline

When 304 is acceptable:

• Inland cities

• Low-humidity environments

• Temporary installations

Our recommendation:
For any coastal project, we supply 316 stainless steel as standard. For extreme marine environments (e.g., directly on the seafront), we use 316L (low-carbon version) for better weldability and corrosion resistance.

Not sure which grade to use?
[Send us your project location] and we'll give you a material recommendation.