Why Don't Magnets Work With All Types of Stainless Steel?
It depends on the crystal structure of the stainless steel. Ferritic and martensitic grades, such as 430, 410 and 420, are magnetic. Austenitic grades, such as 304 and 316, which are common in sinks, cookware and many appliances, are mostly non-magnetic, although bent or machined areas can become slightly magnetic.
Stainless Steel Grades and Magnets
| Family | Common grades | Magnetic? | Where you’ll find it |
|---|---|---|---|
| Ferritic | 430, 409 | Yes | Some appliance panels, trim, exhaust systems |
| Martensitic | 410, 420, 440 | Yes | Knife blades, tools, scissors |
| Duplex | 2205 | Yes | Industrial and marine equipment |
| Austenitic | 304, 316 | Mostly No | Sinks, cookware, many refrigerators, food equipment |
| Austenitic, cold worked | 304 (bent or formed) | Slightly | Edges, corners and formed parts |
Why the Difference?
Stainless steel is iron alloyed with chromium, and often nickel. Adding enough nickel changes how the iron atoms are arranged, into a structure called austenite that doesn’t hold magnetic domains, so magnets don’t grip it. Grades with little or no nickel keep a ferritic or martensitic structure that magnets attract strongly.
Stainless Fridge Won’t Hold Magnets?
Adhesive Magnets
Stick a magnet with 3M adhesive to the item and a second magnet behind a note or photo.
Steel Discs
Attach adhesive steel discs where you want magnets to hold.
Test First
Check the side panels. Many refrigerators use a different grade on the sides than on the doors.