stainless identification

Atlas Knife Company

Atlas Knife Company

Joined
Feb 16, 2010
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1/4" rod from the metal yard. A magnet attracts weakly to it and it's shiny, not the normal matte finish that 304 has from the yard. I think the key is the weak attraction to the magnet.

Thanks in advance for any help.
 
Weakly attracted is a good indication of a cold worked 300 series stainless steel .The shiney surface might also be due to cold working.
 
Cold rolled 304? The yard tells me most of the stuff they stock is 304 construction type stainless. I guess I don't understand how cold rolling negates the nickel and makes it magnetic.
 
Stainless steel has three possible crystal structures = austenite, ferrite and martensite. The last two are magnetic. 304 is normally austenitic but when cold worked it can partially transform to martensite thus become partially magnetic.
 
Mete: Thank you for the explanation. I have a bunch of folder screws that are semi-magnetic that I was also wondering what they are. Now I know, kind of.
 
In recent years 304 coming out of the far east has had increasingly more magnetic characteristics than other sources. I suspect it is not up to spec.

George
 
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