Galvanised steel is carbon steel with a zinc coating and it is unsuitable for a commercial kitchen, because the coating is sacrificial and because zinc has no place on a food contact surface. Stainless resists corrosion through its alloy rather than a coating. They are not alternatives in the same application, and the choice is usually decided by that.
What Is the Actual Difference?
Galvanised protects steel by coating it in zinc, which corrodes in preference to the steel underneath. That is why it works outdoors and why the protection depletes: the coating is consumed over time. Stainless protects itself through chromium in the alloy forming an oxide layer that reforms when damaged, which is why it does not deplete the way a coating does.
Galvanised
- Zinc coating over carbon steel
- Protection depletes over time
- Zinc is consumed by acids and cleaners
- Good outdoors, wrong in a kitchen
Stainless
- Chromium oxide layer, self-reforming
- Does not deplete like a coating
- Withstands kitchen cleaning chemicals
- Suitable for food contact surfaces
Why Can’t Galvanised Be Used in a Food Premises?
Two reasons. The zinc coating is a food contact concern and is not a suitable surface for preparation. And the coating is consumed by the acids and cleaning chemicals in a kitchen, so a galvanised surface fails faster exactly where hygiene matters most. Our food grade stainless steel guide covers what is suitable instead, and our AS 4674-2004 guide covers the fitout standard that governs it.
Where Does Galvanised Belong?
Structural steel in a building, ductwork, outdoor frameworks, and anything where the surface is not touched and the environment is not aggressively acidic. It is a good material in its place. A kitchen is not its place.
Galvanised is not a cheaper stainless. It is a different material doing a different job.
How Does Galvanised Compare on Cost?
It is cheaper per square metre, and the comparison stops there because it is not a substitute. On a like-for-like hygienic surface, the relevant comparison is our benchtop materials guide and the carbon steel vs stainless steel comparison.
Is galvanised ever acceptable outdoors? Yes, on structures and framing, which is where the outdoor BBQ kitchen guide draws the line: galvanised for the frame, stainless for the surface. Coastal exposure shortens galvanised life considerably and pushes the surface toward 316, which the 304 vs 316 grade comparison explains.
How Does Each One Corrode?
Differently, and the difference matters. Galvanised corrodes from the coating inward and gives visible warning, then fails. Stainless corrodes locally where chlorides attack it, which is why tea staining and pitting appear rather than an even deterioration. Our tea staining and pitting guide covers that mechanism.
Frequently Asked Questions
Is galvanised steel rust proof?
It is rust resistant while the zinc lasts. Once consumed, the steel corrodes.
Can galvanised be painted?
Yes, with the right preparation, which does not make it a food surface.
Is galvanised cheaper than stainless?
Yes per square metre, and it is not an alternative for a hygienic surface.
Does stainless corrode at all?
Not in normal kitchen conditions. It can under chlorides, which is what 316 addresses.
Can galvanised be used for ductwork?
Yes, commonly. It is a reasonable material in that application.
Is zinc a food safety issue?
Yes on a contact surface, which is why it is excluded from food premises.
Book a Site Measure
If a specification is open to question, a measure settles which material belongs where. We fabricate stainless steel benches and fitout elements at our Burpengary East workshop. Call 07 3888 7534.
Specification Question?
Tell us the application and we will tell you which material belongs in it, and which one does not.