Stainless Steel Use in Marine Applications

From easy maintenance and a beautiful appearance to outstanding durability and strength, there are plenty of reasons to consider using stainless steel in marine applications and environments

Stainless steel offers a bounty of benefits across a range of environments and industries.

As such, there’s likely stainless steel nearby in your workplace, school, or home.

Use in marine environments and applications is one of the areas where stainless steel excels.

You’ll find it used in everything from offshore platforms and desalination facilities to more cosmetic applications, such as ornamental tubing and boat accessories.

In this guide, we’ll look at why stainless steel is so popular for marine use and some of the most common applications for this popular metal alloy.

Why Use Stainless Steel in Marine Applications?

Before we explore typical uses for stainless steel in marine applications, it’s essential to understand why stainless steel is such a popular choice.

Corrosion resistance is undoubtedly one of the critical reasons why many industries rely on stainless steel components.

Depending on the exact grades of stainless in use, they can even provide excellent resistance in saltwater or acidic environments where many other metals would quickly degrade, leading to component failure or poor visual appeal.

This benefit isn’t limited to pipes, tanks, or other processing systems.

It’s also applicable for structural and decorative elements, such as ornamental tubing, handrails, handles, grab bars, flooring, drainage grates, and more.

In these cases, stainless steel doesn’t simply offer outstanding durability and long service life.

It also provides exceptional flexibility in customizing the appearance of your product, with stainless steel finishes ranging from dull mattes to mirror-finish glosses.

Add ceramic coatings, painting, or powder coating, and the customization options are infinite!

Combine this with a range of stainless steel grades with varying traits and price points, and you have an alloy that offers an outstanding balance of adaptability and affordability for budgets of any size.

Typical Applications for Stainless Steel in Marine Environments

Now that we’ve explored why you might use stainless steel in marine applications, we can explore some of the most common uses we see when supplying industries of all sizes across North America.

Stainless Steel Usage in Docks and Marinas

Whether dealing with lakeside or riverside docks for recreational use or larger commercial docks, stainless steel often plays important roles in the construction and safe operation of docks and marinas worldwide.

Stainless steel, particularly grade 316—sometimes called marine grade stainless steel—can be found in structural and decorative applications in many docks and marinas.

Internally, stainless steel blind bolts, thru-rods, washers, nuts, and bolts can help support the overall dock structure regardless of the materials used.

On the surface, you might also find stainless steel trim, stainless steel slats used as flooring, ornamental tubing used for handrails and supports, and even purely decorative elements such as placeholding tags or signage.

Stainless Steel Ship and Boat Components

From massive commercial freighters on the ocean to pontoon boats on the lake, you’ll find that stainless steel is a prevalent material for components on ships and boats of all sizes.

Typical uses include piping, pulpits, hinges, propeller shafts, railings, accents, fasteners, and shackles.

Stainless piping is increasingly common as a replacement for painted carbon piping for new ship builds. Since stainless piping doesn’t require a second painting process it is a time and installation cost savings over carbon piping alternatives. Lifetime operational costs are also lower due to enhanced durability and reduced maintenance compared with carbon piping.

However, it can also be used for hull plates—both as a solid piece or as hull cladding—or for other larger items like stacks, engine room components, or masts, depending on the boat or ship's design.

As with most stainless steel products, choosing the exact grade of steel used from component to component will provide an optimal balance of corrosion resistance, performance, and cost to help meet safety and budget requirements.

Offshore Platforms and Processes

There are few harsher environments for metal parts and components than you’ll find on offshore platforms.

Between the constant environmental exposure, the regular forces from all directions above, below, and at the surface level, and the saltwater environment, corrosion and component degradation are persistent threats.

Combine this with platforms that are largely isolated, stand hundreds of feet above the water, and weigh tons and you have a situation where part and component failure can become catastrophic very quickly.

Stainless steel is the perfect solution to most of these concerns and sees extensive use in platforms, from larger items like structural supports and catwalks to smaller things like handrails, platforms, and signage.

Choosing the Ideal Grade of Stainless for Your Application

When choosing the perfect stainless steel products for your needs, a thorough understanding of regulatory requirements, metallurgic traits, and other details is essential.

As such, you should always consult a qualified engineer or other professional before making critical purchases and design decisions.

However, the following considerations should help you begin limiting your options and highlight a few candidates from the vast pool of stainless steel pipe products and components available.

  1. Chloride presence and concentrations: This is one of the defining traits of alloys typically used in freshwater or saltwater environments. Choosing ideal grades (such as Grade 316 or 316L stainless steel) will help provide increased service life and operational safety in critical components.

    While 304/304L might offer cost savings upfront over 316/316L parts and components, the molybdenum added to 316/316L’s chromium nickel austenitic grain offers a substantially lower cost of ownership over the life of most components—especially in wet or chloride-rich environments such as those found commonly in marine applications.

  2. Ambient temperatures: While most stainless steel grades perform well across a wide range of operating temperatures, engineers should match grades to their operational environments—especially at extreme hot or cold temperatures—to ensure optimal performance and service life.

  3. Water clarity and cleanliness: Piping fluids with suspended solids, abrasive properties, or contaminants come with unique challenges and corrosion risks. When choosing the ideal steel grade for piping, flanges, and other components, understanding any conditions that might affect performance—such as blocked gates and valves or microbial corrosion—is critical.

  4. Water pressure and movement: Understanding water pressure and movement can impact multiple facets of your final purchase. Structural strength and pressure ratings will vary across most stainless steel piping products. However, understanding processing flow directions, areas of stagnation, and other elements surrounding the movements within the system can also help avoid additional risks, such as crevice corrosion.

Key Takeaways

  • Stainless steel’s corrosion resistance is a reason it is a popular material for use in marine environments and applications.
  • Specific stainless steel grades work better for saltwater use, while others are better suited for freshwater implementation.
  • Uses for stainless steel span a wide variety of products, from smaller items, such as grab bars and handles, to larger items, including catwalks, structural supports, or hull components.
  • Stainless steel components used in docks and marinas include stainless steel blind bolts, thru-rods, washers, nuts, and other fasteners, stainless steel trim, stainless steel slats used as flooring, ornamental tubing used for handrails and supports, and signage.
  • Stainless steel boat and ship components include smaller items such as pulpits, hinges, propeller shafts, railings, accents, fasteners, and shackles. Larger items, such as hull plates, piping systems, stacks, masts, and engine room components, are also candidates for stainless steel use.
  • Offshore platforms are some of the most extreme operating environments in modern industry. Continuous exposure, elemental forces, and high chloride concentrations make marine grade stainless an ideal option to mitigate risk and extend product service life and structural integrity.
  • When choosing the ideal grade of stainless steel for your needs, consider chloride presence and concentrations, ambient temperatures, water clarity and cleanliness, and water pressure and movement.

Unified Alloys serves marine industries throughout North America. Our decades of experience and comprehensive selection of stainless steel pipe and other products allow us to service industries of all sizes. Contact one of our experienced sales analysts today to discuss your needs and explore how we can help you source materials and components for your next project!