Solanum™ Steel

PRE-OXIDIZED WEATHERING STEEL
FOR INTERIOR & EXTERIOR APPLICATIONS

Solanum Steel is Zahner’s pre-oxidized weathering steel, offering rich earth tones and a rugged texture, replicating years of natural aging. Solanum provides a stable, colorful patina that protects the underlying steel, reducing rust runoff and staining on adjacent surfaces. Designed for artists, architects, and designers, Solanum opens new creative possibilities with its enduring aesthetic and versatility.

Custom perforated Solanum screen engineered, fabricated, and installed by Zahner

University of Kansas School of Business in Lawrence, Kansas, featuring Zahner Solanum® Steel.

Designed by Norie Sato, “In the Fold” is an art installation and fence structure built out of Zahner’s Solanum Steel and “Frost White” anodized aluminum.

$WEATHERING STEEL CANOPY FOR GULCH CROSSING IN NASHVILLE.$

The AA Robins Architect-designed Gulf Islands Residence uses Zahner Solanum Steel for both interior and exterior cladding.

LIGHT ENTERS THE SPACE THROUGH THE CUSTOM PERFORATED METAL FOR THE IRVING COURTYARD SCREENWALL.

The Australian Embassy in Jakarta features a variety of metal surfaces.

Solanum adds warmth to a covered entry designed by Andersson-Wise Architects.

The Guggenheim Hermitage Museum in Las Vegas.

Through Zahner’s proprietary pre-weathering process, Solanum Steel achieves deep red and purple tones, combining resilience and beauty for interior and exterior applications. Its stabilized surface prevents corrosion and bleeding, making it ideal for various uses. For interiors, a clear coating creates a smoother finish, while the raw patina is suited for outdoor environments, offering a stylish, low-maintenance choice for modern architectural designs.

Solanum Steel 3D Visualization

Use the visualizer to explore Solanum in 3D environments.

Switch between Exterior & Interior views to see how the sun’s movement will play across a facade or how the Surface will appear from vantage points with a fixed light source.

Exterior

Interior

Solanum Products

Solanum Steel is available with the following Zahner products and services.

Flat Sheets

Solanum Sheet Material

Order flat sheets of Solanum Steel direct from Zahner. Click the button below to see available sizes, thicknesses, and other product details as well as options for submitting a quote request.

Flat Sheet Options

Standard Products

Moda Modular Wall Panel System

Moda combines Zahner’s metal craftsmanship with the convenience of modular design, making it ideal for transforming interior and exterior spaces with its clean lines and Zahner’s signature metal finishes.

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Versatile Systems

Flat Lap System

The aesthetic appearance of shingle or shake with the benefits of metal, Flat Lap is an easy to install, cost-effective shingle solution available in all Zahner Materials.

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View of the massive Solanum-clad doors on the Spaceport America.

Photo © A. Zahner Company.

Versatile Systems

Plate Panel Facade System

The Plate Panel System by Zahner offers a large-panel option that mitigates oil-canning and improves material-yield.

Explore Plate Panel

Versatile Systems

ImageWall® Perforated Metal Panel System

ImageWall perforated metal panel systems enhance lobbies, decorate parking garages, refresh aging exteriors, partition outdoor spaces, and more. Use ImageWall to bring patterns, logos, words, and images of all kinds to life in your designs through durable, affordable perforated metal.

Explore ImageWall

Custom Solutions

Collaborate & Innovate

Whether it’s intricate facades or complex metal artworks, we welcome your most ambitious designs and construction projects. Push the boundaries of what’s possible, turn architectural dreams into tangible success, and create something truly special.

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Documentation

Specs & Info Details Sustainability

Title	File Type	Link
Solanum Steel™ Specs & Usage	pdf	Download
Surfaces Instructions – Storage & Handling	pdf	Download
Surfaces Product Datasheet	pdf	Download
Surfaces Rhino Material File – Solanum	zip	Download
Surfaces Specification	docx	Download
Surfaces Warranty	pdf	Download
Zahner Product Warranty	pdf	Download


Recommended Application	Exterior and Interior
Base Metal (alloy)	weathering steel (A606)
Standard Thicknesses	14 ga 12 ga 11 ga
Approx. Decimal (mm)	.0747” (1.90) .1046” (2.66) .1196” (3.04)
Approx. Weight (lbs/ft2)	3.13 4.38 5.00
COTE (in/in/°F)	7.0 x 10-6
Standard Sizes	4′ x 8’ 4’ x 10’ 4’ x 12’ 5′ x 8’ 5’ x 10’ 5’ x 12’

Declare label for Angel Hair® Stainless Steel | GB-60™ Stainless Steel Zahner® Surfaces

Declare

Declare is a transparency initiative by the International Living Future Institute, providing an “ingredients” label for building products that enables design and build teams to make informed choices.

Red List Free

Products with the Red List Free label are complying with the Living Building Challenge goals of ingredient transparency and industry-wide elimination of all Red List chemicals.

Learn About Declare Reading the Label

Specs & Info

Title	File Type	Link
Solanum Steel™ Specs & Usage	pdf	Download
Surfaces Instructions – Storage & Handling	pdf	Download
Surfaces Product Datasheet	pdf	Download
Surfaces Rhino Material File – Solanum	zip	Download
Surfaces Specification	docx	Download
Surfaces Warranty	pdf	Download
Zahner Product Warranty	pdf	Download

Details

Recommended Application: Exterior and Interior
Base Metal (alloy): weathering steel (A606)
Standard Thicknesses: 14 ga, 12 ga, 11 ga
Approx. Decimal (mm): .0747” (1.90), .1046” (2.66), .1196” (3.04)
Approx. Weight (lbs/ft2): 3.13, 4.38, 5.00
COTE (in/in/°F): 7.0 x 10-6
Standard Sizes: 4′ x 8’, 4’ x 10’, 4’ x 12’, 5′ x 8’, 5’ x 10’, 5’ x 12’

Sustainability

Declare

Red List Free

Products with the Red List Free label are complying with the Living Building Challenge goals of ingredient transparency and industry-wide elimination of all Red List chemicals.

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Use Solanum Steel in Your Project

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Solanum Steel Manufacturing, Properties, and Applications

Solanum Steel is a pre-oxidized weathering steel (Corten) surface developed by Zahner. The surface is produced by accelerating the natural weathering process and stabilizing the result. Solanum Steel provides artists, architects, and designers with a range of resonant tones on an enduring surface.

One of the well-recognized challenges of using steel in architecture is its propensity for the material to rust or oxidize. Although many appreciate the warm hues of weathering steel, nobody likes it when the material’s color bleeds onto other surfaces. The Zahner preweathered steel process reduces the material’s tendency to stain adjacent surfaces.

Fabrication: Corten Steel or Solanum Steel

Solanum Steel, weathering steel, copper-bearing steel, and COR-TEN (Corten) are all names for a durable subset of steel alloys (A-242 and A-588). These steel alloys offer long-term endurance in exterior conditions. Instead of corroding away, as these materials surfaces oxidize, the oxidized layer becomes a protective layer.

The issue with fabricators who use standard corten alloys is that it takes a few years of exterior exposure before the material’s rust condition stabilizes. During this process, the material will bleed.

Solanum Steel resolves this challenge by bringing the natural weathering steel alloy into an insoluble and stable state. This preweathered surface is accelerated in a dedicated Zahner facility for producing sheets and custom fabricated corten forms in Solanum Steel.

How Solanum Steel is Manufactured

The typical alloy used in Solanum Steel is ASTM A-588, developed as an advancement over the original alloy used in COR-TEN, a trademark of U.S. Steel. Since the material was first made public, it has been utilized by architects on countless projects.

The Solanum Steel process begins at the raw steel ingot. Zahner has a close relationship with both the steel mill and the rolling mill, and can influence the quality of the surface long before the raw sheet arrives. This ensures that the material derives from specific alloying components and that the base raw material is cast to exacting specifications.

Then, the ingot is processed by Zahner’s rolling mill partner, whose finesse with steel ensures that the surface is properly treated to avoid streaks, rings, and discolorations.

Zahner patina engineers inspect each and every plate surface. The bare Solanum Steel is then cleaned and prepared to eliminate oxides and contaminants. If this step is not carefully followed the finish will not hold up.

Once properly prepared, Zahner force the surface to an initial ferric oxide. This finish is slightly orange in color and is characterized by a crusty texture.

An orange patina is not as permanent as a dark patina. A patinated steel showing yellow and light orange colors will rub off and continue to bleed and stain adjoining surfaces, unless sealed with a durable coating.

Solanum Steel seen under a microscope. Note the flaky appearance of the typical weathering steel patina.

PHOTO © A. ZAHNER COMPANY.

Zahner allows the orange-toned oxide to grow to a point before removing the majority of it from the surface. The surface is then exposed to a proprietary bath with specific atmospheric conditions to develop a hydrated oxide form.

At this stage, the steel surface becomes insoluble. The material is then arrested with a final bath that inhibits and slows oxidation to a standstill.

Sealing Solanum Steel

In some circumstances, the Solanum Steel material can be sealed. This is often desired for trafficked environments where people will touch the surface.

For interior applications of Solanum Steel, the material can be sealed with a clear coating to provide a softer touch. However, for exterior applications, it is recommended to leave the material unsealed.