Neodymium magnet puzzlement (2023 Update)

[Arthur 51]

Hi. Just had a small sheet of .5mm thick stainless steel 305 delivered for a project I'm starting. I expected it to be compatible with neodymium magnets. But nope!

Am I missing something?

Thanks.

[Fredxx]

Yes, stainless steel 305 is non-magnetic.

[Arthur 51]

FFFFFuck!

Thanks.

[polygonum_on_google]

Paint it reddish-purple. Won't actually help but could make it magentic.

[Fredxx]

Some stainless steels are magnetic, perhaps armed with that knowledge you can get what you need?

[Richard]

:)

[Brian Gaff (Sofa]

In what way? If you mean non ferrous, that very much depends on the sort of Stainless it is. We used to have many debates about this issue at Racal Marine. You or probably going to get involved in spec numbers and standards if you want it to be really non ferrous. You don't have this with Ally sheet!

The reason Racal were upset was the radar system can be near the compass, requiring a re calibrate if it has any residual magnetism. Brian

[Tim Lamb]

In message <rmbsir$7rp$ [e-mail], "Brian Gaff (Sofa)" [e-mail]> writes

In my limited experience, SS which can be hardened is magnetic. The blades of our cutlery knives are magnetic but not the handles.

[polygonum_on_google]

Perhaps Wiki would help?

[Harry Bloomfield Esq]

Kitchen knives, generally..

[Fredxx]

My newsreader seems to have broken this thread!

Suggests that professional knives made out of X50CrMoV15 and most others that require tempering to retain an edge are magnetic.

BICBW

[Chris Hogg]

No, you are right. I have a set of posh cutlery (bought by way of a minor celebration to replace a motley collection of knives, forks etc when we moved into a new property). The knife blades, stainless steel, are magnetic, the handles, also ss, are not.

[AnthonyL]

Define which stainless steel.

"There are five families of stainless steel: ferritic, martensitic, austenitic, duplex, and precipitation hardening. These names are derived from the crystal structure of the steels, which determines their metallurgical behavior."

Then work your way through the grades:

[Chris Hogg]

At least one of those, maybe more!

How the f**k should I know?

[Fredxx]

I was making the assumption that, as per the article I gave, stainless steels that can be tempered and create an edge tend to be magnetic.

Please do feel free to find an alternative article that dispels that claim.

[Chris Hogg]

This gives some sort of explanation as to why the different types of SS are magnetic or not:

In broad terms, ferritic, martensitic and duplex stainless steels are magnetic, while austenitic stainless steels are not.

Then of course there's ferromagnetic and antiferromagnetic, not forgetting paramagnetic and diamagnetic.

[AnthonyL]

Exactly. That was the problem we had in our Engineering Degree when doing the Metallurgy module - "What is stainless steel". From nearly

50yrs ago all I remember is that much what is called stainless steel is neither stainless nor steel. Can't help much more than that I'm afraid, but I'm sure someone else might.

[Jeff Layman]

+1

I've always thought the term "stainless" to be a misnomer. Even touching SS can sometimes leave a fingerprint which isn't easily removed. I've always thought that the German term "rost frei" (rust free) is somewhat more accurate for domestic SS items (unless you're at sea...).

[Jeff Gaines]

I have some solid silver coasters which I "won" in my first divorce, they're magnetic.