Galvanized steel vs. stainless steel

Galvanization is a process designed to help steel resist corrosion and provide protection to keep it looking and performing great.

However, these are all key traits of stainless steel as well.

So which is better for your next project?

In this guide, we’ll compare stainless steel and galvanized steel across a variety of common considerations and use types to help highlight the strengths and weaknesses of these two popular steel variations.

WHAT IS GALVANIZED STEEL ANYHOW?

Before we can compare them, it’s essential to understand how galvanized steel is made.

Essentially, galvanized steel is simply zinc-plated steel.

There are multiple ways to galvanize steel parts and components, but they all provide similar results as long as they are correctly performed.

The most common method of galvanizing steel is hot-dipping.

In this process, standard steel is dipped in molten zinc, creating a layer of zinc that bonds with the surface of the steel, providing protective benefits and an appealing appearance.

Electro-dipping and thermal diffusion methods are also used when parts are particularly small or complex.

This layer of zinc serves the same purpose as the passive layer of chromium oxide on the surface of stainless steel, helping the metal resist corrosion and repel scuffs, dings, and other minor physical abuses.

This also means that you end up with a layered finished product instead of a fully alloyed product like stainless steel.

SO IS GALVANIZED STEEL AS CORROSION RESISTANT AS STAINLESS STEEL?

In general, no.

However, this will depend on the specific situations in which you plan to use your galvanized or stainless steel parts.

Galvanized steel offers excellent resistance against water and chlorine but pales in comparison to stainless steel’s corrosion resistance when dealing with marine environments.

The protective layer on galvanized is also not self-healing like the passive layer on stainless steel.

This means that over extended periods, galvanized parts are generally less durable than stainless ones.

However, even if the zinc layer on a galvanized component is damaged, it will still serve as a sacrificial cell in galvanic corrosion processes, encouraging rust formation on the damaged zinc areas instead of the underlying steel.

In general, stainless will offer better corrosion resistance and offer it for a longer period as well.