I've always found that MOST stainless steel has little or no attraction
to a magnet. How reliable is this test?

Is there quality stainless steel that IS drawn to magnets?

Why is most stainless steel not attracted to magnets?

While we're on the subject of stainless steel, what are it's general
properties aside from not rusting due to oxidation? Is or can it be as
hard as tool grade steels? Are there some neat links where I can find
out about different kinds of steel? This has always been a facinating
topic to me.

Dan

Dan Musicant wrote:

I've always found that MOST stainless steel has little or no attraction
to a magnet. How reliable is this test?

Is there quality stainless steel that IS drawn to magnets?

Why is most stainless steel not attracted to magnets?

While we're on the subject of stainless steel, what are it's general
properties aside from not rusting due to oxidation? Is or can it be as
hard as tool grade steels? Are there some neat links where I can find
out about different kinds of steel? This has always been a facinating
topic to me.

Dan


Austenitic stainless steel is not magnetic. It has to do with the grain
structure. If you heat
any steel up to its austenitic phase it will lose is attraction to
magnets. Other grades of
stainless like martensitic and precipitation hardening stainless are
attracted to magnets.
They are both hardenable by heat treatment too.

Fred

On Sat, 30 Aug 2003 17:36:54 GMT, Dan Musicant wrote:
I've always found that MOST stainless steel has little or no attraction
to a magnet. How reliable is this test?

Not very.

Is there quality stainless steel that IS drawn to magnets?

Yes. 400 series stainless is magnetic. 300 series is not.

Why is most stainless steel not attracted to magnets?

The 300 series has a different grain structure (austenitic) which
won't form magnetic domains (this is the form regular steel takes
when heated above the Curie point). The 400 series has a
martensite grain structure which will allow magnetic domains to
form. The 400 series is also heat treatable. It is what is used
for stainless knife blades.

While we're on the subject of stainless steel, what are it's general
properties aside from not rusting due to oxidation? Is or can it be as
hard as tool grade steels? Are there some neat links where I can find
out about different kinds of steel? This has always been a facinating
topic to me.

The 400 series can be hardened, but it can't be hardened quite as
much as plain carbon steel of the same carbon content because of
the presence of chromium (the latter is what makes it stainless).

Gary

mikee wrote:

The 300 Series stainless steels are non-magnetic.


With one exception. Work hardened 300 series is slightly magnetic. Test
a SS spring and see, or test a thin piece of sheet before and after bending.

I get that all the time about 302 stainless wire brushes. The drawing
process will cause attraction to a magnet. I imagine work-hardening or
other physical manipulation to the stainless will do the same.
I always tell people to spark-test suspected stainless and compare the
sparks to known carbon steel.

"Dan Musicant" wrote in message
...
I've always found that MOST stainless steel has little or no attraction
to a magnet. How reliable is this test?

Is there quality stainless steel that IS drawn to magnets?

Why is most stainless steel not attracted to magnets?

While we're on the subject of stainless steel, what are it's general
properties aside from not rusting due to oxidation? Is or can it be as
hard as tool grade steels? Are there some neat links where I can find
out about different kinds of steel? This has always been a facinating
topic to me.

Dan

Thee is only one problem wih all these answers. They are all wrong.
300 series can be quite magnetic if work hardened. Try a magnet on SS
wire rope sometime. I know of a batch of 304 SS that could not be
demagnitized despite the supplier's efforts. The supplier was
Jorgenson Steel back before they chnaged their name to EJM. The
general rule is that 300 series SS are not magnetic in the annealed
condition. This is a general rule and the SS forgets to follow it
sometimes. Lots of other metals like inconel are virtually impossible
to tell from SS, with a magnet. Leigh@MarMachine

On Sat, 30 Aug 2003 18:46:41 GMT, ff wrote:

an Musicant wrote:
:
:I've always found that MOST stainless steel has little or no attraction
:to a magnet. How reliable is this test?
:
:Is there quality stainless steel that IS drawn to magnets?
:
:Why is most stainless steel not attracted to magnets?
:
:While we're on the subject of stainless steel, what are it's general
:properties aside from not rusting due to oxidation? Is or can it be as
:hard as tool grade steels? Are there some neat links where I can find
:out about different kinds of steel? This has always been a facinating
:topic to me.
:
:Dan
:
:
:Austenitic stainless steel is not magnetic. It has to do with the grain
:structure. If you heat
:any steel up to its austenitic phase it will lose is attraction to
:magnets. Other grades of
:stainless like martensitic and precipitation hardening stainless are
:attracted to magnets.
:They are both hardenable by heat treatment too.
:
:Fred

I assume, then, that when this austenitic phase steel cools below a
threshhold temperature it will once again be attracted to magnets?

mikee wrote:

The 300 Series stainless steels are non-magnetic. This includes 302, 304,
316, etc. Here is a link that talks about it:
http://www.spiusa.com/Ref001/austenitic.html. If you have some stainless
steel utensils or bowls that are not attracted to magnets, they are
austenitic stainless and almost certainly one of the 300 series grade of
stainless. Stainless steel gets its corrosion resistance from its chromium
content (and to a lesser extent its nickel content). Deep draw operation
products (sinks, bowls, etc.) are usually made from 300 series stainless
steel. Knives, which need to maintain a sharp edge are made from a different
composition that can be thermally heat treated (hardened). This kind of
stainless is attracted to a magnet.

Why are some stainless types attracted to magnets and not others? I've read
the text books and know about the grain structures and the carbide types, but
still think this is one of neater mysteries around. Personally, I think God
just wanted to irritate mankind in trying to figure out why it works this
way.

Mike Eberlein






For us speak slow and use small words types -
Cutlery made from stainless sticks very well to the fridge magnet.
The same magnet won't stick to a stanless sink or bowl.

YMMV





Some really are rustless iron, not stainless steel

Dave.