Better Testing Methods Advice

As well as a magnet I also use scratch testing to distinguish between aluminium and steel where pieces are thin and it isn't so easy to tell the difference in density.

I saw my local yard do this to some Hard Drive lids i took in recently. I thought they were aluminium but he scratched them and said "nope, they are stainless steel".



What am i looking for when i scratch different metals? How deep does the scratch need to be?

Regards
Neil

Originally Posted by Ballymoss

I saw my local yard do this to some Hard Drive lids i took in recently. I thought they were aluminium but he scratched them and said "nope, they are stainless steel".

What am i looking for when i scratch different metals? How deep does the scratch need to be?

Regards
Neil

Take the two pieces of metal -try and pick a corner or sharper edge and use it to try to scratch the other metal. If it is harder or the same hardness it will scratch the metal. If it is softer it will leave a line of its own metal across the other surface like lead would do on paper. Swap round to recheck. The scratch is easy to distinguish from abraded metal. It will be much shinier and also when you run a finger nail over it you will feel it. Many hard drive lids have a dual metal casing. Aluminium housing and a stainless steel surface glued on.