The magnet test is one of the most persistent shortcuts in material identification, and one of the most misunderstood. It is quick and convenient, which is exactly why it gets overused. A magnet distinguishes stainless steel families; it does not confirm grade, corrosion resistance, or quality.
Austenitic grades such as 304 and 316 are generally non-magnetic in the annealed condition, though they can become partially magnetic after bending, forming, or other cold work. Ferritic grades such as 430 and martensitic grades such as 410 and 420 are magnetic by nature. Each family carries a distinct balance of corrosion resistance, formability, hardness, and cost, which is why they appear in such different applications.
For procurement teams and engineers, the practical point is that stainless should be specified and verified by grade and documentation rather than by a field test. The Metal Supermarkets stainless steel guide offers a useful overview of the main grades, their properties, and typical uses, and it is a solid reference for training newer staff. The full article is linked in the comments.
Metal Supermarkets Atlanta (Northwest) supplies stainless steel cut to size with no minimum order from our Marietta location. How does your team verify stainless grades on incoming material? #StainlessSteel #MetalIndustry #QualityControl
Authentic close-up of a magnet held against two pieces of stainless at the Marietta location, one where it sticks and one where it doesn't. A shot of polished stainless sheet or bar on the racks also works. Real photos strongly preferred over stock. No Google Drive image folder is set up for this client yet, so request a real photo from the Marietta location.
Canva text suggestion: "The Magnet Test Identifies Families, Not Quality" or "Specify Stainless by Grade, Not by Magnet"