Stainless steel, magnetic or not?

Discussion in 'General Firearms Discussion' started by Earnshaw, Jul 5, 2015.

  1. Earnshaw

    Earnshaw Member

    Speaking here of the grades/alloys used in firearms (not refrigerator doors and fasteners :D) , does anyone here have a stainless steel firearm which doesn't attract a magnet? I own several SS guns by various makers and every single one will hold a magnet. I've often wondered about the advice given to folks to use a magnet as a test for stainless steel in firearms and whether those proffering this advice have ever actually tried it themselves.
  2. talon

    talon the banned wagon

    There are multiple alloy combinations that make up stainless steel. From a metalugy point of view, stainless steel is divided into two main types: Ferritic and Martensitic stainless steels. There are different types of stainless steels: when nickel is added, for instance, the austenite structure of iron is stabilized. This crystal structure makes such steels virtually non-magnetic and less brittle at low temperatures. For greater hardness and strength, more carbon is added. With proper heat treatment, these steels are used for such products as razor blades, cutlery, and tools.
    Other alloys, however, remain magnetic. Some people think that you can determine if a metal is stainless by using a magnet to determine if the metal has a magnetic attraction or not. This is simply not true.
    Ferritic and Martensitic stainless steels ARE magnetic.
    Austenitic stainless steels are non-magnetic.

    Most stainless barrels (and sometimes receivers) in use today start with steel in the 400 Series of stainless steel. 400 Series alloys are considered ferritic and martensitic chromium alloys. They are magnetic.
    Last edited: Jul 5, 2015

  3. Smart

    What he said!

    I used to work for a spring manufacturer and remember the sorters at the scrap yard taking a magnet to our stainless scrap and trying to dump it in the steel tote. Always had to get the boss man out who knew exactly what were bringing.