SST .625 dia Cold Rolled 303 bar and Magnetism

[JRKH]

How much "magnetism" would be acceptable in .625 dia Cold Rolled 303 bar?
I know that some magnetism can be introduced through cold working - - but I don't know how to quantify this....

We have some of the above bars that are exhibiting a pretty strong attraction to a rare earth magnet and were rejected by both our saw operator and two of our best Quality techs as being too magnetic. But - this is really kind of an experience and feel thing and I am wondering if we can create something more quantifiable.....

How much magnetism can be introduced just in cold rolling? Is there a way to quantify this?
Is a rare earth magnet a fair test of this material?

Any info would be appreciated.

James

 

[Miner]

Re: SST and magnetism...need some education please

This has good coverage on the issue.

 

[JRKH]

Re: SST and magnetism...need some education please

Thanks for the article. I have saved it for future reference.
Unfortunately - It isn't as "practical" as I hoped.

My concern is really one of - how much magnetism is likely to be introduced into a 300 series SST by the Cold Roll process?

At what point would the magnetism be enough to suggest that the material is not a 300 series Stainless.

Is there anything that can help me with this?

James

 

[normzone]

Re: SST and magnetism...need some education please

I'm afraid I can't offer any quantifiable help, only my experience that I've seen lots of 300 series SS that would hold a magnet - so it doesn't necessarily mean the material is not 300.

I used to have a dye penetrant kit that also contained a small analog meter that would respond to magnetism - I used it to find welds in assemblies that had been polished so well you could not tell where the welds were. I don't remember any pertinent numbers though.

Do you have one of those chemical test kits that can be used to determine material type? Acid on a paper, electricity applied, more chemicals on the paper, sample then compared to reference guide? That should be able to tell you something.

 

[JRKH]

Re: SST and magnetism...need some education please

Don't have one, but sounds like something worth looking into.

The sense I'm getting from my research so far is that there really isn't much quantifiable out there....

James

 

[normzone]

Here's a similar kit to the one I used to use. Is there a question about whether the material is 316 or 304? Or is there a requirement regarding magnetisim?

I don't know if this will solve your problem, but it's a handy tool to have.

http://www.koslow.com/metal-alloy-id.html

And the manual:

http://www.koslow.com/manuals/1499.pdf

 

[JRKH]

Here's a similar kit to the one I used to use. Is there a question about whether the material is 316 or 304? Or is there a requirement regarding magnetism?

No there isn't a requirement on the magnetism....
It is just being confusing to the fellows on the floor.
I was hoping that there might be something fairly simple and preferably quantifiable that I could share with them and with the quality team to get us all on the same page.


For the time being I have told everyone that CR 300 series stainless can have a little magnetism so do not use a rare earth magnet to check.
HR 300 stainless steel should NOT have any magnetism at all - but to only use a rare earth magnet if there is a serious doubt.

I don't know if this will solve your problem, but it's a handy tool to have.

http://www.koslow.com/metal-alloy-id.html

And the manual:

http://www.koslow.com/manuals/1499.pdf

Thanks for the links.

James