Ted Mooney, P.E. RET
- Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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What would make Brass magnetic?
Q. I recently purchased a vase that is brass, at least that I was told it was brass. I happen to have a neo-magnet and it became attracted to it and stuck to the vase. It wasn't a strong attraction and it came off easily but it stuck to it non the less. My questions are, "Is it possible that some other base metals were added to the making of the brass vase that would make it magnetic?" Also, "could it be brass electroplating?" One last question-"Is there a test to determine if my vase is somewhat brass all the way through?" I am upset that the company informed me that it is Brass and I suspect that they lied to me. I just want to know that if it's anyway possible that this could be brass or if it's common that some brass are attracted to magnets by the way it's made.Any help would be appreciated. Thanks to all.
Lou Abbatiellohobbyist - Lindenhurst, New York
January 19, 2009
A. You cannot make brass magnetic. I suspect you have got a steel based product that has been plated with brass or even painted with a brass coloured lacquer Trevor Crichton R&D practical scientist Chesham, Bucks, UK A. Brass and its alloys are non-ferrous (no iron content). If it is even slightly magnetic it is most likely brass plated. On the underside (bottom) of vase scrape with a sharp screwdriver to see if there is a different color metal that appears. You will probably see a silvery metal. Ferrous metals are not normally alloys in brass, and I've never heard of any that would make the brass magnetic. Mark BakerFellow plater - Syracuse, New York |
A. Sorry to be the one to break the news, but it sounds like you got taken. There isn't any "magnetic brass" that I know of - it's plated ware. Dave Wichern Consultant - The Bronx, New York A. It's probably got a plated nickel layer, then a brass topcoat. Electroplated nickel is attracted to a magnet, especially if it's thick... It doesn't sound like solid brass. George Brackett III- Maine |
A. Hi all
Lou is speaking of a neodymium magnets and they are really powerful. I have no problem accepting George Brackett's explanation. Sounds like a vase might well be zinc or aluminum and subsequently nickel and brass plated.
Luck & Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. This is a follow-up question to whether or not brass is magnetic. The responses I have received were all appreciated. The follow-up question is, "Is it remotely possible when making the brass by combining copper and zinc that they also added iron to the mix?" Instead of just copper & zinc, it's copper, zinc & iron all mixed together in a pot and then poured. Thanks to all.
Lou Abbatiello [returning]- Lindebhurst, New York
January 26, 2009
A. I think you are clutching at straws. Copper and zinc are the components of brass; if it contains iron of any degree that would make it magnetic, you have cheap second rate brass.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
A. Stumbled on this thread and thought I'd toss my answers into the mix from a metallurgical perspective. First of all, non-ferrous doesn't mean that a material contains 0.0% iron, only that it is not iron based. Brass alloys are classified as non-ferrous because they are copper based. Brasses are primarily alloyed with zinc, but can also contain tin, manganese, nickel, lead, and iron. Iron and nickel are both ferromagnetic, manganese is paramagnetic.
Secondly, Neodymium magnets are very strong. If you had an iron based substrate that was brass plated, the magnet would have a strong attraction right through the plating.
Thirdly, the fact that the magnet is very strong means that it will be weakly attracted to very small amounts of magnetic material in the brass. I have a known sample of a copper base alloy, SAE 430B, sitting on my desk right now that has a neodymium magnet stuck to it. SAE 430B contains 2 to 4% iron, and the magnet has a fairly strong attraction (strong enough to hold 3 business cards in place).
Bottom line is I believe you have a vase that was made from a brass alloy that contains some small percentage of iron and/or nickel.
- Minster, Ohio
February 5, 2009
A. Actually, WikiAnswers says that brass may contain 0.2 - 0.4% iron as an ordinary contaminant - and that's enough to get a noticeable attraction from o Neodymium-based 'super-magnet'. all of the 'commercial grade' brass bar that I've played with will be weakly attracted to a super-magnet.
Brian Spencerteacher - Adelaide, South Australia, Australia
August 17, 2009
Jim S: SAE 430b is a manganese bronze; not brass.
George Hillier Sr.construction - Highland, Indiana
February 8, 2012
A. You said you used a neo magnet, which is one of the stronger magnets. It did not "stick" to it in the sense of a true ferrous metal would be attracted to a magnet, But the neo magnet creates an electro field in line with the falling (gravity works) of the magnet which can if the magnet is strong enough seem to be magnetic. This is only a force of force created by the electrons in the brass only slightly trying to line up with the N and S poles of the neo magnet, thereby not "sticking" to the non ferrous metal but trying. In theory if the size of the neo magnet was so large in comparison to a relatively small piece of brass, it would stick.
Or perhaps another scenario posted by others could be correct.
- Long Beach, Mississippi USA
February 12, 2014
A. Jim, I think you are right. I have found that a neo magnet will be attracted to plated or painted steel almost as strong as bare steel. A couple years ago I bought some cheap brass fluid fittings on eBay. I noticed a neo magnet had a weak attraction to them. I ground into one and found that there was no color change throughout the cross section. I tried a magnet on some higher quality brass and found no attraction. After doing some research I found that a small amount of iron is permissible in brass alloys. I suspect that cheap brass has higher iron content than higher quality brass. I agree with you that this is likely causing the weak attraction of a magnet.
Dave Bezaire- San Luis Obispo, California
March 19, 2023
A. Could be aluminum bronze which looks very similar to Brass or even gold that often contains small amounts of iron.
This and other alloys are typically referred to as copper alloys instead of brass or bronze so as not to cause so much confusion.
Aluminum Bronzes are copper-base alloys containing 6% to 12% aluminum and varying amounts of iron, nickel, manganese and/or silicon alloying additions that provide a broad range of mechanical properties -- from high ductility to the high-strength levels of high-tensile manganese bronze.
Copied and pasted from website at the following link:
www.wbcastings.com/non-ferrous-alloys/brass-bronze/aluminum-bronze/#:~:text=Aluminum%20Bronzes%20are%20copper%2Dbase,of%20high%2Dtensile%20manganese%20bronze
- Lakeland Florida
August 24, 2023
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