SS304 vs SS316 Invisible Grill Wire: Why Grade Matters
By Sushil Shinde, Founder & Installation Head, SafeNest · Updated November 2026
Short answer: SS316 contains about 2% molybdenum, which makes it far more resistant to salt and chloride corrosion than SS304. In Mumbai, Thane, Navi Mumbai and anywhere near the sea or a creek, SS316 is the right choice. SS304 is acceptable for some inland Pune flats. Avoid SS201, which can rust quickly.
| Grade | Key alloy | Corrosion resistance | Use it for |
|---|---|---|---|
| SS316 (marine grade) | Chromium, nickel + ~2% molybdenum | Excellent, including salt air | All Mumbai/MMR flats, sea-facing, high-rise, pool-side |
| SS304 | Chromium + nickel | Good inland, weaker against salt | Some inland Pune installations |
| SS201 | Low nickel, high manganese | Poor; rust spots within months | Not recommended for grills |
How to check what you are getting
- Ask to see the wire spool label and supplier invoice showing the grade.
- Get the grade, wire diameter and strand construction (7×7 or 7×19) written on your quote.
- A magnet test is not proof: some 316 and 304 wire becomes slightly magnetic after cold drawing. Rely on paperwork and warranty.
- Ask for a written rust warranty. A supplier confident in genuine SS316 will give one.
Wire thickness
2 mm suits most windows and balconies up to mid-rise floors. 2.5 mm is a good all-round choice. 3 mm is recommended for high-rise towers above about the 15th floor, wide spans and sea-facing flats where wind load is higher.
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