Steelhouse Group Oy adopts Outokumpu's duplex stainless steel for Finken Bridge in Helsinki, Finland

"Finken Bridge isn't your average infrastructure project. Located beside Korkeasaari, it serves as both a visual landmark and a symbol of future-proof urban mobility. We're proud to be involved in building something unique that lasts for generations — not just in material, but in significance and purpose," rejoices Sami Nummela, Business Area Manager at Steelhouse Group Oy.

The alliance involves multiple stakeholders, including Steelhouse Group Oy, the manufacturer and installer of the stainless steel railings, and the City of Helsinki, as the investor. For Steelhouse, the collaboration with Outokumpu was a continuation of the long-term partnership, also evident in the iconic Atlantinsilta Bridge, for example.

"A vital city is also a growing city. The Finken Bridge is part of Helsinki's efficient and well-functioning public transport network, supporting both climate action and the city's growth strategy. In the local context, the bridge means smoother connections and improved accessibility," says Ville Alajoki, Project Director at the City of Helsinki.

Solid together, from vision to reality 

At Steelhouse Group Oy, the Finken Bridge project began with BIM modelling and moved through engineering design, material planning, fabrication, and on-site installation.  The project demanded managing complexity and pushing for excellence. What makes it complex is not a particular single step but the orchestration of everything, from aligning with site timelines to coordinating with other contractors on location.

"As a global leader in sustainable stainless steel, Outokumpu had an essential role in helping us succeed. Outokumpu's partnership and technical expertise helped us deliver a successful project throughout. Their tailored solutions reduce waste, increase manufacturing efficiency, and support sustainability," Nummela emphasizes.

The Finken Bridge railings feature nearly 290 meters and 52 tonnes of weatherproof Forta DX 2205 duplex stainless steel, the most popular duplex product on the market. It offers excellent resistance to uniform and localized corrosion, as well as stress corrosion cracking, in combination with high mechanical strength. At Steelhouse, each piece underwent a detailed process, including laser cutting, bending, forming, and welding, followed by glass bead blasting and pickling.  

"Materials supplied by Outokumpu arrived in time and customized sheet lengths, optimized for fabrication, which was a big advantage—less material waste, smoother production," Nummela notes. 

"In long-term and large-scale projects, conditions change repeatedly, requiring resilient partners. Also, we must consider a vast number of variables, ranging from environmental to technological and economic, and everything in between. It's gratifying to note that the Finken Bridge project stayed on schedule and within budget," Alajoki adds.

A bridge that also carries the environment

Using Forta DX 2205 ensures long-lasting, maintenance-free railings with a clean, aesthetic finish that resists corrosion under varying environmental conditions. The material eliminates the need for painting or repainting, significantly reducing both maintenance costs and the risk of paint waste entering the sea.

Due to mechanical strength and corrosion resistance, the material has a low lifecycle cost and aligns with the City of Helsinki's long-term vision for achieving carbon neutrality. The duplex grade Forta DX 2205 was explicitly chosen for Finken Bridge due to its proven resistance to the harsh coastal environment and its ability to deliver on both function and form.

"It was important for us to work with a domestic partner like Outokumpu. They provided the right grade, the right delivery capabilities, and most importantly, stainless steel with the lowest carbon footprint in the industry," Nummela says. 

In a landmark project like the Finken Bridge, being able to back up the material choices with data and durability is essential. Outokumpu's duplex stainless steel is accompanied by a Product Specific Carbon Footprint (PSC) certificate. The emphasis on long-term value over short-term gains underscores the material selection process.

As Finken Bridge nears complete handover, work continues within the Crown Bridge alliance, where the scale multiplies significantly. The ongoing work reinforces the partnership's commitment to sustainable urban development and the strategic use of domestic, low-carbon materials in demanding public projects. 

"It's great that we have both a Finnish steel supplier and a railing manufacturer capable of helping the City of Helsinki achieve its long-term goals," Alajoki concludes.

The benefits for Steelhouse Group Oy:

• Trusted partnership: Continued collaboration with Outokumpu enhanced operational confidence and delivery precision. 
• Efficient manufacturing: Custom-length sheets reduce waste and streamline fabrication, saving time and resources. 
• Technical excellence: Duplex stainless steel ensures exceptional mechanical strength and corrosion resistance. 
• Sustainability leadership: Contribution to carbon-neutral infrastructure reinforces Steelhouse Group’s green positioning. 

The benefits for the City of Helsinki:

• Resilient infrastructure: Long-lasting, corrosion-resistant railings reduce maintenance and replacement needs. 
• Environmental compliance: The use of low-emission stainless steel supports the city's climate neutrality targets. 
• Visual & functional harmony: Durable materials maintain aesthetic appeal in harsh coastal conditions. 
• Support for domestic industry: Local sourcing aligns with Helsinki's values of sustainability and economic responsibility.