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TECHNICAL
Why are my stainless-steel mixers rusting?
By
Patrick Gordon, technical manager, Splashworks
Stainless steel rusts because, despite its name, it’ s not entirely immune to corrosion.
It’ s made primarily of iron, along with chromium and other metals. The chromium in stainless steel forms a thin, protective layer of chromium oxide when exposed to oxygen. This layer is usually enough to protect the metal from rusting.
• It’ s highly resistant to rust and corrosion in most environments, but in very harsh or saline conditions( like marine environments), it can still rust.
• Protecting stainless steel from rusting involves minimising the factors that contribute to corrosion and maintaining the material’ s protective oxide layer.
All images by Google Free Images
Several ways you can help prevent stainless steel from rusting 1. Regular cleaning and maintenance
• Clean often: Regular cleaning is essential to remove dirt, salt and contaminants that could cause corrosion. Use mild soap and warm water with a soft cloth or sponge. Avoid abrasive cleaners that could scratch the surface.
However, if this protective layer is damaged – due to physical damage, exposure to harsh chemicals or very salty environments – it can break down and the iron underneath can begin to rust. In extreme conditions, like exposure to high humidity, chlorides( like salt), or acidic environments, even higher-quality stainless steel can start to rust.
So, while stainless steel is generally more resistant to corrosion than regular steel, it’ s not completely rust-proof under all conditions.
There’ s no stainless steel that is 100 % immune to rust, but some grades are much more resistant than others. The key to preventing rust lies in the alloy’ s composition, particularly the amount of chromium and nickel it contains. The higher the amounts of these metals, the more resistant the steel is to corrosion.
• Use a non-abrasive cleaner: Abrasive cleaners or steel wool can damage the protective oxide layer, making it more susceptible to rust. Opt for non-abrasive, pH-neutral cleaners.
The best type of stainless steel, highly resistant to rust, is Type 304 Stainless Steel( 18 / 8).
• This is the most common stainless steel used for kitchen appliances, sinks and food-grade containers. It contains 18 % chromium and 8 % nickel.
www. plumbingafrica. co. za @ plumbingonline @ plumbingonline @ PlumbingAfricaOnline May 2026 Volume 32 I Number 03