Magnet and non magnetic stainless steel

[mjm46@bellsouth.net]

I recently ordered some White Lightening Vent Liners from Chambers. When putting them away I still had a couple fo WL liners that I purchased eslewhere. I bumped the older liners into my scriber with the magnet head and wam they stuck like glue. The Chambers liners were unaffected, which is what I expected from Stainless. The old ones are indeed stainless of some kind they don't brown. 

My question is which is the best for vent liners the magnetic stainless steel or the non-magnetic stainless steel, or doen't it matter? I thought all stainless was non-magnetic. My refrigerator front won't take frige magnets.

[halfstock]

High carbon content affects magnetic's.

[Ben I. Voss]

Non magnetic stainless is the 300 series and magnetic is 400 series. Halfstock is right- the 400 stainless has carbon that makes it heat treatable for hardness, the 300's don't. The 300's are more stainless generally than the 400's, both could make a good vent liner. Anyhow, that's what I think I know about that!

[Dphariss]

Non magnetic stainless is the 300 series and magnetic is 400 series. Halfstock is right- the 400 stainless has carbon that makes it heat treatable for hardness, the 300's don't. The 300's are more stainless generally than the 400's, both could make a good vent liner. Anyhow, that's what I think I know about that!

Carbon is not magnetic.
Magnetic stainless has more IRON in it then non-magnetic.
.

Dan

[woodburner]

I am under the assumption that magnetic and non-magnet stainless steel
is related to amount of nickle in the alloy.  The more nickle, the lass magnetic. Tim

[Pennsylvania Dutchman]

As Dan said it the iron in the stainless that is magnetic. It is my understanding that all heat treatable stainless has iron and carbon. I should check my steel books to be sure. I don't think the 300 series stainless steels have any iron in them at all, therefore they technically aren't even steel though we call it stainless "steel". The 300 series stainless would probably stand more erosion from flame than the others but would also gall easier on installation if a lube wasn't used. The iron content is also the reason most all but 300 series stainless will rust or stain, 300 will stain only if in contact with carbon steel.
Mark Poley

[Dphariss]

White Lightnings are made of 303.


Dan

[Dphariss]

Stainless Steel - Grade 303

Chemical Formula

Fe, <0.15% C, 17-19% Cr, 8-10% Ni, <2% Mn, <1% Si, <0.2% P, >0.15%S

All stainless has some iron IIRC but the non-magnetic alloys have a small enough percentage that they will not attract a magnet. Or if so only very slightly.

Dn

[Dave Faletti]

Differences in crystal and/or atomic structure determine whether iron is magnetic or not.  The percentage of iron in a steel alloy will make a difference but it isn't the dominant factor for the night and day difference with some alloys.

[Jim Kibler]

Iron is magnetic as well as nickel.  It is the atomic structure of the material that determines whether it is magnetic.  Increased nickel content stabilizes and contributes to an austenitic structure.  Austenite is non-magnetic.

[Dphariss]

So thats how that works. Magic through chemistry.
I was wondering how they made the FE non-magnetic.


Dan

[Bennypapa]

I don't think the 300 series stainless steels have any iron in them at all, therefore they technically aren't even steel though we call it stainless "steel".
Mark Poley

I don't think that is correct. Here are a couple of steel grade guides that quote chemistry. They show that many stainless steels are about 70% iron.
http://www.onlinemetals.com/stainlessguide.cfm
http://www.mcmaster.com/#=h4prms

As stated it is the structure of the steel that determines magnetism.

But back on topic, I can't see how magnetism could affect function as a vent liner. You'd be better served paying attention to the hardenability of the alloy than the magnetism. You wouldn't want an alloy that could be cold hardened so much that it becomes brittle.

[Dphariss]

 You wouldn't want an alloy that could be cold hardened so much that it becomes brittle.

There in lies another problem.
But apparently its minor.

But then few liners are installed with a clean out opposite them that allows looking at the INSIDE of the liner.


I made one with a thicker wall....
Dan

[Ben I. Voss]

Read all about it here:http://en.wikipedia.org/wiki/Stainless_steel