# Why 2205 Stainless Steel Is the Gold Standard for Coastal Railing If you live near the water, the material your railing is made from isn't just an aesthetic choice, it's a long-term investment decision. Salt air, moisture, and chloride exposure can destroy ordinary metals in a matter of years. That's why Viewrail uses 2205 duplex stainless steel as the foundation of its coastal railing systems. Here's what makes it different, and why it matters for your home. If you are still comparing infill types, see [What is Cable Railing?](/guides/about-stairs-and-railing/what-is-cable-railing.md) and [Should I Buy Cable Or Rod Railing?](/guides/planning/choose-the-right-railing-for-your-project/cable-railing-vs.-rod-railing-which-one-is-right-for-your-project.md). If you already know you want cable, compare [Express vs. Signature Cable Railing: Which One Is Right for Your Project?](/guides/about-stairs-and-railing/railing-system-deep-dives/express-vs.-signature-cable-railing-which-one-is-right-for-your-project.md).
#### Why Stainless Steel Grade Matters Not all stainless steel is created equal. The term covers a broad family of metal alloys, each with a different chemical composition and a different ability to resist corrosion. The grade, such as 304, 316, or 2205, describes the specific mix of elements in that alloy and directly determines how it will perform in demanding environments. For decades, the railing industry treated 316 stainless steel as the benchmark for corrosion resistance. It worked well in most applications, and it still does outside of coastal zones. But when Viewrail first began installing 316 posts in the harshest coastal locations, the results were disappointing. Warranty claims started coming in as early as three months after installation, sometimes stretching to three years. When the team went back to inspect, they found pitting at the tops of the posts and corrosion beginning around the mounting holes, exactly the spots where moisture and salt could pool and go to work. Something better was needed. #### How the Industry Measures Corrosion Resistance: The PREN Scale The steel industry uses a standardized measurement called the **Pitting Resistance Equivalency Number (PREN)** to compare how well different alloys hold up against chloride-induced corrosion. The formula weighs the concentrations of three key elements — chromium, molybdenum, and nitrogen — each of which plays a distinct role in protecting the metal's surface from pitting. A PREN score of 32 or higher is generally considered the threshold for full resistance to saltwater environments. Here's how the common grades compare: | Alloy | PREN Score | Recommended Use | | --------------------------- | ---------- | -------------------------------- | | 304 Stainless Steel | \~18–19 | Interior applications only | | 316 Stainless Steel | \~25 | Exterior, non-coastal | | 2205 Duplex Stainless Steel | \~34–35 | Coastal and extreme environments | 316 falls well short of that threshold, leaving it vulnerable in truly salty environments. 2205 duplex clears it comfortably, and that gap is the difference between a railing that holds up for decades and one that starts showing corrosion within a year or two. Viewrail still uses 304 stainless steel for interior applications or exterior locations at least five miles from saltwater. For anything closer to the coast, 2205 is the right call. #### What Makes 2205 Different 2205 is a duplex stainless steel, meaning it has a two-phase microstructure (austenitic and ferritic) that delivers both high strength and exceptional corrosion resistance. Its elevated chromium, molybdenum, and nitrogen content are what push its PREN score well above the saltwater threshold that 316 can't reach. In practice, that difference shows up in real-world performance. After Viewrail switched to 2205 and replaced several corroded 316 installations, the long-term results were dramatically better. The same alloy has long been trusted in offshore oil rigs, marine infrastructure, and pedestrian bridges over brackish water — industries where material failure isn't an option. #### Viewrail's 2205 Coastal Railing Systems For projects within five miles of the coast, Viewrail offers two coastal-ready railing configurations, both built around 2205 stainless steel posts: **Rod Infill System** * 2205 duplex stainless steel posts (brushed or powder coated) * ¼" 2205 stainless rod infill — available in brushed stainless or Coastal Onyx * Isolators to prevent metal-to-metal contact * Eck anti-corrosion treatment for added salt protection * Compatible with aluminum posts finished in AAMA 2605 powder coat as an alternative to stainless posts **Cable Infill System** * 2205 duplex stainless steel posts (brushed or powder coated) * 5/32" 316 stainless steel cable infill * No isolators required — the all-stainless combination eliminates galvanic corrosion risk The ¼" rod infill is worth highlighting for coastal projects specifically: unlike woven cable, which is made up of many individual wire strands with small gaps between them where salt and moisture can become trapped, each rod is a single hollow tube with a smooth, uninterrupted surface. There's no place for corrosive elements to work their way in, and the rods won't sag over time. If you are comparing coated aluminum to stainless steel for a coastal build, see [What Is Powder Coating? Viewrail's Process and Finish Options Explained](/guides/about-stairs-and-railing/railing-system-deep-dives/what-is-powder-coating-viewrails-process-and-finish-options-explained.md). If you want a broader post-material comparison, see [Wood vs Metal Railing Posts: Which Is Better for Cable Railing?](/guides/planning/choose-the-right-railing-for-your-project/wood-vs-metal-railing-posts-which-is-better-for-cable-railing.md).
#### Warranty Coverage Viewrail backs coastal railing systems built with 2205 stainless steel with a **structural warranty** for projects within five miles of the coast, and a **finish warranty** covering fading, adhesion failure, and permanent structural corrosion. See full details on our [warranty page](https://www.viewrail.com/warranty/). Surface-level oxidation, staining, or discoloration that can be removed through cleaning is not considered corrosion under the warranty terms, structural corrosion that permanently compromises the metal is what's covered. Regular maintenance with **Marine 31 Polish and Sealant** is required to keep that coverage valid. #### How to Maintain Your 2205 Stainless Steel Railing 2205 is built to last with minimal effort, but regular maintenance keeps the finish looking sharp and is required to maintain your warranty. Here's what Viewrail recommends: **Every 6 Months: Polish and Seal** 1. **Rinse thoroughly** with fresh water to remove salt, dirt, and debris. A pressure washer works well for this step. 2. **Apply Marine 31 Stainless Steel Liquid Polish** to restore the brushed finish and remove any light oxidation or surface staining. Work in small sections with a terry cloth applicator. 3. **Rinse the polish away completely.** Residual polish will interfere with the sealant. Wiping the surface down with rubbing alcohol after rinsing ensures it's fully clean. 4. **Apply Marine 31 Stainless Steel Liquid Sealant** using a clean, dry foam applicator. Apply a thin, even coat, allow it to dry for at least five minutes, then buff off any residue with a clean cloth. The acrylic-based sealant protects against UV exposure and salt degradation for up to six months. **Routine Cleaning** * Wipe down posts and infill periodically with a microfiber cloth and mild soapy water. Avoid harsh chemical cleaners, bleach, and abrasive materials which can damage the brushed finish. * Use distilled water when possible, as tap water can leave mineral deposits or streaks. * Clear leaves, pollen, and other debris that collects around post bases or between rods. These trap moisture against the metal and accelerate surface staining. * In snowy climates, clear snow and ice from exterior posts and infill promptly. **What to Watch For** * **Surface tea staining or discoloration** is common in coastal environments and is not structural corrosion. It can typically be cleaned or polished away. * Pay extra attention to **mounting holes and post tops** — these areas are most prone to trapping moisture. Make sure the sealant coat is well applied around these spots. * If you notice pitting that catches a fingernail, or corrosion that appears to be compromising the metal structurally rather than just the surface, contact Viewrail to evaluate a potential warranty claim. For broader upkeep guidance, see [How Do I Maintain Cable Railing?](/guides/maintenance/how-do-i-maintain-cable-railing.md) and [How To Take Care of Your Exterior Cable Railing](broken://spaces/YiIQ32eyDEEMOXuUTd8u/pages/sDCvrBiZSKlucPlO1vTm). #### A Note on Long Island and Coastal Connecticut For most coastal locations, 2205 stainless steel posts are warranted and recommended. For projects on **Long Island, NY**, Viewrail requires 2205 stainless steel posts within one mile of the coast to maintain warranty coverage. Aluminum posts are excluded from warranty within that distance. If your project is in Long Island or coastal Connecticut, check with a Viewrail representative before finalizing your material selection to make sure you have the right system for your exact location. #### The Bottom Line If your project is within 5 miles of saltwater, the grade of stainless steel in your railing matters more than most people realize. 316 was the industry standard for a long time, but it doesn't meet the PREN threshold for true salt resistance. 2205 duplex stainless steel does, and with the right maintenance routine, it's the most durable, longest-lasting stainless railing option available for coastal homes. ### Related topics #### Compare materials * [What is Cable Railing?](/guides/about-stairs-and-railing/what-is-cable-railing.md) — Get the full overview of cable systems, materials, and use cases. * [Should I Buy Cable Or Rod Railing?](/guides/planning/choose-the-right-railing-for-your-project/cable-railing-vs.-rod-railing-which-one-is-right-for-your-project.md) — Compare corrosion resistance, maintenance, and install time. * [Wood vs Metal Railing Posts: Which Is Better for Cable Railing?](/guides/planning/choose-the-right-railing-for-your-project/wood-vs-metal-railing-posts-which-is-better-for-cable-railing.md) — Choose the right post material for coastal exposure. #### Choose the right system * [Express vs. Signature Cable Railing: Which One Is Right for Your Project?](/guides/about-stairs-and-railing/railing-system-deep-dives/express-vs.-signature-cable-railing-which-one-is-right-for-your-project.md) — See which product line supports coastal projects. * [What Is Powder Coating? Viewrail's Process and Finish Options Explained](/guides/about-stairs-and-railing/railing-system-deep-dives/what-is-powder-coating-viewrails-process-and-finish-options-explained.md) — Learn when powder coat makes sense near salt air. #### Maintain your railing * [How Do I Maintain Cable Railing?](/guides/maintenance/how-do-i-maintain-cable-railing.md) — Review routine cleaning and inspection. * [How To Take Care of Your Exterior Cable Railing](broken://spaces/YiIQ32eyDEEMOXuUTd8u/pages/sDCvrBiZSKlucPlO1vTm) — See post and finish care for exterior systems. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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