On 1/11/2018 3:12 PM, Emanuel Berg wrote:
Duane wrote:

Depends on the iron content in the stainless
among other things. Some are magnetic and
some are not.

OK, at least the A4 stainless steel boltware
I have isn't magnetic.

So now we're at:

aluminium - nonmagnetic;

steel - magnetic, only

stainless steel - sometimes magnetic

How can anything be easier than using a magnet?
Well, it seems how easy something is to do
isn't the only parameter...

The appearance of the metals is often a clue, as can be their response
to tapping with a small object.

I think you should develop some experience telling them apart. Perhaps
take a magnet to various metal objects around your home. Many of your
kitchen utensils will probably be stainless steel - things like forks,
spoons, knives, perhaps measuring cups. I suspect few if any will be
aluminum.

In my kitchen, I find that knives are magnetic. They're almost certainly
martensitic stainless steel, which can be hardened. Our measuring cups
and measuring spoons are non-magnetic, which means they're probably
austenitic. Most of our metal bowls and pots are non-magnetic, but one
pot is magnetic. But all are very different in appearance from aluminum.
Also, obviously, aluminum is noticeably less dense. Unless it's
anodized, it's also softer (i.e. easier to scratch).

Also check the bikes you have available. On all but the cheapest bikes,
the caliper brakes, cranks, rims, hubs, brake and shift levers will
probably be aluminum. Usually, only spokes and perhaps cables are
stainless steel objects on bikes. Cranks, rims and things that might be
steel on lower-quality bikes are much more likely to be chrome plated
instead of made of stainless steel. Stainless tends to be expensive and
much more difficult to work with.

Admittedly, it's not 100% easy to tell the difference every time, since
there are various coatings available. But experience can teach you a lot.

BTW, why are you interested in telling the difference between handlebar
materials?


--
- Frank Krygowski