Duplex rules the waves

Silja Kudel


Swedish Steel Yachts (SSY) needed a super-strong, sustainable material to complement their innovative patented ultra-light hull design.


Stainless steel enables an extremely thin hull without compromising strength. The use of Forta duplex stainless steel means the boat requires no painting, coating or other maintenance.


Steel grade: Outokumpu Forta SDX 2507 duplex

The joy of boating is the freedom of the open water, but the downside is the struggle of scraping barnacles off a chipped hull. A new ultra-light stainless steel boat designed by Gävle-based Swedish Steel Yachts (SSY) is a boater’s dream come true: the world’s first maintenance-free yacht. The 10.5-meter-long vessel is the first of its kind constructed from stainless steel.

The material chosen for the boat is Outokumpu Forta duplex stainless steel, which makes the hull lightweight yet super-durable.


Strong as a Viking

The combination of SSY’s patented design with Outokumpu’s specific stainless steel grade delivers an extremely thin structure without compromising an ounce of strength. The yacht weighs only 2,000 kilograms, one-third of the average weight of common carbon steel boat. The flexible, resilient vessel moves with fluid control even in the choppiest waters.

Thanks to its unique design and steely strength, the hull absorbs the force of powerful waves just as Viking boats did one thousand years ago. It can also withstand icy and other extreme conditions at sea.


Goodbye to paintbrushes

Many owners of fiberglass and carbon steel boats lament the time and resources wasted on maintenance. The beauty of stainless steel is that it completely eliminates the need for painting and coating.

Added to being sustainable, the stainless hull is attractive and has a mirror finish to ensure that water elements don’t attach on the boat surface. “Our vision was to construct a boat that honors the long shipbuilding history in the Gävle region in Sweden and combine it with our desire to build strong and sustainable boats. The use of stainless steel enabled us to meet both of these goals,” says Håkan Rosén of SSY.

The material for the project, Outokumpu Forta SDX 2507 duplex stainless steel, was delivered by Outokumpu’s units in Nyby, Avesta and Degerfors in Sweden.

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Automotive and transportation

In transportation, today’s solutions must be dynamic enough to carry us to the future. Safe, strong, economical, durable and sustainable: Stainless steel delivers a new dimension of unmatched performance.


Stainless steel is the clear choice for use in marine environments – particularly for vessels that are ever lighter, stronger and easier to clean and maintain


The Forta range contains duplex and other high strength stainless steels that enable thinner structures and weight reduction (measured in Rp0.2 > 400 MPa. PRE 16 to 43).

Avesta, Sweden

Fueled by a high-octane blend of advanced technology and a long, proud tradition, the Avesta mill showcases precision performance. One of Outokumpu’s fully integrated production sites, Avesta redefines excellence.

Nyby, Sweden

Steelmaking is deeply ingrained in Nyby. Nearly 200 years after the mill’s founding, Nyby continues to be recognized worldwide for uniquely customized, exceptionally high performance stainless steel.


Stainless steel is a superb material for sustainable solutions as it is 100% recyclable, efficient and long-lasting. Our vision is to become the customers’ first choice in sustainable stainless steel.

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