Key points at a glance
- Stainless steel protects itself with a passive layer that renews itself in contact with air.
- The most common causes of rust spots are extraneous rust, chloride and the wrong cleaning agents.
- Light spots can be removed with stainless steel cleaner in the direction of the grain.
- Where there is a lot of salt or acid, V4A is the more resistant choice.
Why stainless steel normally does not rust
Stainless steel contains chromium. In contact with air, this forms a wafer-thin passive layer that protects the steel against corrosion. If it is damaged, it renews itself with oxygen.
Rust occurs when this layer is permanently disrupted, or when foreign iron lies on the surface and rusts there.
The most common causes
| Cause | How to recognise it | What helps |
|---|---|---|
| Extraneous rust | fine brown spots, often after work with steel tools or steel wool nearby | remove early with stainless steel cleaner, avoid steel wool and steel brushes |
| Chloride | pitting where salt, brine or chlorine-based cleaners are left standing | rinse off salt and cleaner residue; choose V4A for heavy exposure |
| Wrong cleaner | stains after bleach, chlorine cleaner or descaler containing hydrochloric acid | only use products suitable for stainless steel and rinse well |
| Deposits | rust under seals, rubber mats or residue that stays damp | keep surfaces dry, lift and clean mats regularly |
With chloride, the right grade helps: V4A contains molybdenum and is much more resistant. More on this in our guide V2A or V4A.
How to get rid of rust stains
Light stains
Clean with stainless steel cleaner or a mild abrasive cleaner and a soft cloth, working with the grain. Then wipe over with clean water and dry.
Stubborn spots
On ground finishes, a fine abrasive fleece used with the grain helps. Polished surfaces are better treated by a specialist.
Heavy rusting
Here the surface is pickled and passivated. This is a job for a specialist, as pickling agents contain acids.
Four rules against rust
Read more about daily cleaning in our guide Cleaning and caring for stainless steel.
Questions about rust on stainless steel
Is stainless steel really rustproof?
It is corrosion-resistant as long as the passive layer remains intact. Under unfavourable conditions, such as chloride or extraneous rust, rust stains can still appear.
Is rust a sign of poor-quality stainless steel?
Usually not. It is often extraneous rust that only sits on the surface. If rust keeps coming back after cleaning, a different grade such as V4A may make sense.
Can I use steel wool for cleaning?
No. Steel wool leaves fine iron particles that rust on the stainless steel. Use soft cloths or abrasive fleece without metal content.
Which stainless steel is the better choice where there is a lot of salt?
Where salt, brine or acid regularly come into contact with the surface, V4A (1.4404) is much more resistant than V2A. On request, we make work tables, base units and built-in units from V4A. More under work tables and sink units.
Sources and further information
- Frequently asked questions about stainless steel (German Stainless Steel Information Centre (Informationsstelle Edelstahl Rostfrei))
- Information sheets from the German Stainless Steel Information Centre (Informationsstelle Edelstahl Rostfrei)
As of September 2026. This information does not replace individual advice.
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