If you’re installing street furniture, bollards, benches, shelters, or railings near the sea, ordinary steel may not be your best choice for long-term durability. On promenades, in marinas, and generally in coastal towns or any environment exposed to salt air, salty spray, or de-icing salts, stainless steel shines, both literally and figuratively speaking.
The specificity of coastal installations lies in the salt-laden air, spray, moisture, and constant humidity, which increase corrosion risk. In those salty conditions, stainless-steel products made from 316 (or marine-grade) alloy remain the most reliable option. While standard stainless-steel grades already offer good corrosion resistance, marine-grade stainless carries additional resistance against chloride-induced corrosion from salt in the air or water.
For instance, when a public walkway, a marina’s deck railings, or a seaside transport shelter are exposed to salt spray, using a product in standard stainless steel might lead to pitting or surface corrosion over time. By contrast, marine-grade ensures that even after years of exposure, the structure retains its integrity — with minimal rusting and minimal maintenance.
In many cases, the small extra investment for marine-grade stainless pays off in long-term savings: fewer replacements, less maintenance, and sustained aesthetics that suit contemporary coastal architecture or public-realm design.
Understanding Stainless Grades: 304 vs 316 (Marine-Grade)
Stainless steel is divided into several grades based on the metal’s crystalline structure. The two popular series are the 200 and 300. Grades serve as indicators about what you can expect from a specific steel, like shortcodes for composition and properties. The 200 are chromium-manganese-nickel alloys, and the 300-grade series are chromium-nickel alloys. Most outdoor stainless-steel street furniture is made from one of the two most common stainless grades: 304 or 316. On the surface, they may look similar — but their performance in coastal or high-salt environments differs significantly.
Grade 304 is a very common stainless steel alloy (roughly 18–20% chromium + ~8–11% nickel). It offers decent corrosion resistance, high tensile strength and great durability. This is typically fine for general outdoor use. For inland, dry or sheltered sites (parks, suburban streets, rural areas), 304 often performs well enough.
Grade 316 (Marine Grade) adds around 2–3% molybdenum to the mix. It may sound like a small change, but it makes a big difference. Marine-grade stainless steel is highly durable and has excellent corrosion and oxidation resistance, especially against harmful acids, alkalis, and chlorides. This makes it particularly good at resisting chloride-induced corrosion from salt water or salt air. It also has better tensile strength and can resist pitting and crevice corrosion more effectively. All qualities you would benefit from in coastal zones, poolside areas, marinas, piers and seaside public installations.
In practice, 304 may be acceptable where salt exposure is minimal or where the furniture is sheltered or inland. But for anything near the coast — walkways, railings, bollards, shelters — 316 marine-grade is almost always worth the extra cost. Using 304 near the sea often leads to visible rust spots or reduced lifespan.
Whenever specifying stainless steel for coastal projects, it’s wise to ask whether the steel is marine-grade — meaning 316 (or equivalent) — rather than assume stainless steel is sufficient.
Where to Use Stainless (316) on Coastal Projects — and Why It Matters
For coastal and seaside public-realm installations, 316 stainless steel is especially good for many street furniture items, like:
Bollards and safety posts. On promenades, piers, or coastal parking areas, bollards face salt air, occasional splash, and aggressive weather. A marine-grade stainless bollard resists rusting far longer than regular coated steel or even standard stainless.
Benches, seating, planters, public-realm furniture. Salt air corrodes metal over time; stainless steel ensures the seating and public furniture keep their appearance and integrity. For seaside parks, coastal cafes, or beachfront promenades where aesthetics matter — this is a big plus.
Railings, handrails, structural supports. For marinas, coastal walkways, seaside piers, and accessible zones, metal railings and supports must resist salt-induced corrosion. Marine-grade stainless steel offers peace of mind, especially when used in public settings and with minimal maintenance.
Columns, fittings, external fixtures. Any exposed metal — column protectors, corner guards, structural supports — benefits from the extra resistance of 316 stainless steel to avoid pitting, corrosion, or unsightly rust marks over years of exposure.
As a general rule: if a structure is within reach of sea breeze, salt spray or de-icing salts (common even in colder coastal climates), assume that marine-grade 316 stainless is the correct spec.
When the Extra Cost Is Worth It — And When It’s Overkill
Marine-grade stainless costs more than standard 304. But the extra cost is usually justified when installations are in or near coastal zones, or in any environment with salt exposure (salt spray, coastal humidity, de-icing salts, etc.). The long-term durability, lower maintenance and aesthetic durability of 316 often pay off.
On the other hand, if installations are inland, sheltered from salt exposure, in low-humidity zones — or in non-critical, low-cost applications — then 304 stainless (or even less expensive materials) may suffice. In those cases, the cost savings may outweigh the benefits of marine-grade stainless.
Stainless steel remains one of the most desirable materials in modern urban design — but when you expect salt, spray and humidity, not all stainless steels are equal. For any installation exposed to sea air, salt spray or de-icing salts, the choice of stainless steel grade matters far more than it might first appear. Marine-grade stainless (316) offers corrosion resistance, longevity, and minimal maintenance, making it the smart choice for coastal installations: from railings, benches and bollards to shelters, canopies and external fixtures.
If you’re specifying street furniture for a marina, seaside promenade, coastal town centre, or similar — investing a little more today can save a lot on maintenance, refurbishment, and replacements down the line.