Close this search box.

Bonderized Steel: What You Need to Know!


Bonderized steel, also known as paint grip steel, was created for the rainwater goods industry. Paint adheres easily to this particular steel product, so homeowners can paint their rain gutters, downspouts, and roof flashing to match the rest of their house.

When purchasing galvanized bonderized steel, it’s important to remember that this product should be painted. The dull, matte grey color has become popular, but bonderized steel can develop white rust, scratch easily, and have an inconsistent finish without paint. The best time to paint it is immediately after it’s installed.

We’re a trusted national supplier and processor of bonderized steel. We also offer a variety of steel products, including cold-rolled steel, aluminized steel, galvanized steel, stainless steel, and galvannealed steel. We provide comprehensive steel finishing services to meet your project requirements, including painted, perforating, or embossing finishes. In addition, we can deliver slitting, blanking, toll processing, or cut-to-length processing services. Learn everything you need to know about this type of steel, and give us a call or fill out a contact form for a quote!

What is Bonderized Galvanized Steel?

Bonderized steel begins as galvanized steel, which is steel hot dipped in molten zinc. This layer of zinc prevents the underlying metal from rusting and being subjected to corrosion. 

But what is bonderized steel? Also called bonderized galvanized steel, it has a matte grey finish due to the bonderizing process, which involves putting it through a phosphate bath where the coating chemically reacts with the steel, creating a layer of zinc phosphate. It can later be sealed with a chromate conversion coating.

Bonderized steel was designed for the rainwater industry. This steel’s surface is pre-primed for paint application, allowing soft metals on houses like rain gutters and downspouts to be painted to match the rest of a home. The nature of bonderized steel extends the life of paint because it provides a “sticky” and textured surface that paint can easily grip, even without additional primers.

While other types of steel can be painted, bonderized steel was explicitly created for paint.

Bonderized Steel vs Galvanized

While galvanized steel can be painted, bonderized steel should be painted. 

Galvanized steel is designed to withstand wear and tear from moisture without any additional coating. It has a naturally speckled appearance that resembles a sponge painting. It can be painted, but it must be primed appropriately first.

Bonderized galvanized steel, on the other hand, is galvanized steel that has been run through a phosphate bath, crystalizing the coating and making it the perfect surface for paint—no priming necessary. If left unpainted, bonderized steel will develop white rust.

Need Bonderized Steel For Your Next Project?

If you need bonderized steel processed for your next project, contact us below to coordinate with one of our experts. We can discuss your project needs and provide you with the bonderized steel you need at the best price.  

Request a Quote!

More To Explore