One question we hear a lot at FortheChef.com is, why isn’t my magnet sticking to my stainless steel (and the follow-up question is, is this really stainless steel)? Truth is, not all stainless steel is magnetic.
In short, nickel content in certain stainless steel compounds – in this context within 18/10 and 14/1 stainless steel – will cause the stainless steel to not be magnetic. Read below for more information as to why that is.
Without going into the details behind ferritic and austenitic stainless steels (check out Scientific American for a wonderful article on this), here’s the low-down on the most commonly seen food-safe stainless steel varieties.
Stainless steel comes in various food-safe grades. For kitchen products, the main variations are 18/10 (also known as 18/8 or 304 Stainless Steel), 18/0 (also known as 430 Stainless Steel), and 14/1 (also known as 200 series Indian Stainless Steel). There’s also 13/0 stainless steel, which is commonly used in table knives.
The numbers 18/10, 18/0, and 14/1 are shorthand means of denoting the content balance of chromium and nickel (there are some other components of the second number, but for simplicity, we will stick with nickel).
Chromium is typically used for the sheen that stainless steel is known for; the greater the chromium content, the “whiter” the stainless steel tends to be.
Nickel is typically used for added rust and corrosion resistance. The nickel content is what causes the magnet to not stick to the surface of the stainless steel! As a result, 18/10 and 14/1 stainless steel, which tends to make up a large proportion of kitchen products, will not be magnetic.
This bears the question: why can stainless steel be induction-compatible if induction cooktops rely upon magnetism?
Great question – this is because induction-compatible cookware (whether tri-ply or encapsulated bottom) often has an outer layer of 18/0 magnetic stainless steel that is in contact with the induction cooktop. Read more about tri-ply cookware here.