Better Testing Methods Advice

I have been researching alternative methods for testing my metals other than the well-known "magnet test" and "spark test." I am having trouble finding some good procedures for this. I have two ideas and any input or advice would be greatly appreciated.
One: In college chemistry I learned about how to find limiting reactants/stoichometry and I would like to develop a chemical process to find out the exact molecular makeup of the substances that I have using other chemicals.
Two: I thought about using a sensitive enough Ohm meter to test the resistance of the metals that I have and compare them to known resistance levels.

Any thoughts or ideas on accomplishing these tests?

Thanks,

Mikey

Welcome to the board Mikey.

May I urge you to introduce yourself in the introduction section. The regulars tend to be more forth coming with a proper introduction.

I like the resistance idea. Looking forward for others to chime in on this.

Though magnets and spark testing might seem a little primitive, they work for the vast majority of metal that we come into contact with. The metals usage often gives more clues to other metals like Nickel alloys. If you want to look into chemical testing of rarer metals, the guys in the goldrefining forum are much more knowledgeable.
Measuring resistance would give pretty clear results for metals but there are so many alloys as well as plated metals. Also the differing thickness of materials would also affect results, I would think this would give an unreliable result though I may attempt some values in the new year.
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. All alloys of iron are harder than all alloys of aluminium so this is easy. It can also sometimes be used to tell between aluminium and zinc though these are much closer in hardness.

I usually torch test everything metling it usually reveals what it is at least to me. I can tell the difference between 304 and 316 SS just by melting it. If you are really stumped by something just take it to the yard and make them hit it with the niton gun. I can usually just tell by looking at something what it is but I have been doing this for way to long.

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Originally Posted by PistoneScrapProcessing

I usually torch test everything metling it usually reveals what it is at least to me. I can tell the difference between 304 and 316 SS just by melting it. If you are really stumped by something just take it to the yard and make them hit it with the niton gun. I can usually just tell by looking at something what it is but I have been doing this for way to long.

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Have you noticed that non magnetic SS becomes magnetic near the cut or melted zone.

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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.

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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

SS is much harder than AL. So test it out on a few items and you will find the differences easily. Mike

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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

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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.

maaaaan do I ever feel stupid. I never thought of this

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Many hard drive lids have a dual metal casing. Aluminium housing and a stainless steel surface glued on.

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Yep, kind of a horseshoe looking thing, or half-round.