How did I magnetize it?

[metalworker77]

I'm in the beginning process of making a knife blade and something odd happened; I accidentally magnetized the piece of flat bar as I was grinding the rust off it. I am excited about it; I have never magnetized anything before! I know that iron can be magnetized when heated and quenched, but I never thought that the bar would get hot enough for something like this to happen. Maybe it was something else that magnetized it except the heat? vibration? Anyway, I kind of like it, could be a useful feature for a knife! Will the magnitization stay? How about if I heat it again in the forge?

[easilyconfused]

I have had pieces left by the side of the fire magnetize. Never thought to check to see if it stayed though and I don't have any knowledge about magnets other than they work.

[Maillemaker]

Magnetism is all about the alignment of the iron atoms in the stock. So, yes, if you don't do anything else with the iron, the molecules in your stock will stay magnetically aligned. If you heat it up, the grain structure (alignment of molecules) will change. Heck, even dropping the iron repeatedly will shock the molecules out of alignment.

[pkrankow]

You can magnetize iron or steel by impact too.

Phil

[Steve Sells]

Magnetism can also be induced from the magnetic fields of the electric motor and the wiring windings ... as well as the grinding belts themselves creating static, and a magnetic feild... the possibilities are nearly endless.