Hey folks, ever caught yourself wondering if the RA brass foil you’ve been eyeing for that electrical project, art piece, or custom hardware part is magnetic? As a longtime RA Brass Foil supplier, this is one of the most common questions I get from our customers—from small-time makers to big industrial teams building transformers or precision electronics. Let’s break this down straight, no stuffy textbook jargon, and answer that question once and for all, plus why it actually matters for your work. RA Brass Foil
First off, let’s get a couple basics out of the way so we’re all on the same page. Brass is an alloy, right? That means it’s a mix of copper and zinc, sometimes with tiny amounts of other metals like lead, tin, or manganese added to tweak its properties. RA brass foil is just a specific type rolled thinner for tight applications—usually 0.001” to 0.010” thick, perfect for stuff like battery tabs, shielding, or decorative trim. Magnets, on the other hand, rely on unpaired electrons in a material’s atomic structure to create that pull. Ferromagnetic materials (the ones that stick to magnets) have those unpaired electrons aligned in domains, so when a magnetic field comes near, they lock in place. Non-ferromagnetic materials? Their electrons pair up, so there’s no net magnetic pull, no matter how strong the magnet is.
So here’s the short answer, and it’s the thing we tell every customer asking this: Standard RA brass foil is not magnetic. Wait, but hold on—don’t close this tab just yet, because that “standard” part is key, and I’ve seen way too many people get tripped up by that. Let me explain the why, and then the edge cases that might confuse you.
First, copper itself is diamagnetic. That means it actually repels magnetic fields just a tiny, tiny bit—like, so faint you can’t feel it with a fridge magnet. Zinc? It’s also diamagnetic. So when you mix those two to make standard brass, those diamagnetic properties dominate. There’s no iron, nickel, or cobalt in the mix (the only common metals that are strongly ferromagnetic) in RA brass foil that we supply. That means a regular bar magnet won’t stick to it, period. I’ve tested this a hundred times—hold a fridge magnet up to a sheet of our RA brass foil, and it just slides right off, no pull at all. No magic trick here, just basic alloy chemistry.
But wait, why do some people say brass is magnetic? Let’s clear that up. A lot of lower-grade brass products, like cheap hardware store brass nails or thin brass sheet, have trace amounts of iron accidentally mixed in during manufacturing. Those tiny iron bits are ferromagnetic, so that brass will stick to magnets. But that’s not “true brass” as far as industrial or precision applications go—and definitely not the RA brass foil we supply. We control our alloy composition super closely, so there’s no extra iron or other ferromagnetic metals sneaking into the mix. That’s a big part of why customers trust us for projects where magnetism is a no-go.
Now, let’s talk about why this question actually matters. If you’re working on electrical components, for example, magnetic materials near coils can cause eddy current losses—extra heat that wastes power, or even messes up the signal in small electronics. That’s a huge deal for things like battery packs or sensor parts, where even a tiny power loss adds up. If you’re building a decorative project, like inlay work for furniture or jewelry, a magnetic brass piece would be a pain—you don’t want your inlay pulling a magnet off the fridge, right? For shielding applications, non-magnetic brass is perfect because it blocks electromagnetic fields without distorting them, unlike ferrous metals that can actually bend and redirect fields in unintended ways.
I’ve seen this play out a lot with our customers. A few years back, we had a maker reach out because their first prototype used a cheap brass sheet that stuck to their assembly line magnets, and it ruined a batch of prototype parts. They switched to our RA brass foil, and suddenly everything worked exactly as designed. Another customer was building custom RFID tags, which rely on non-magnetic materials to read properly—magnetic brass would have thrown off the tag’s frequency, so they specifically needed a non-magnetic option, which our foil delivered. That’s why the “is it magnetic?” question isn’t just a random fact—it’s a make-or-break detail for a lot of projects.
Wait, but let’s cover one more common confusion: what about induced magnetism? Sometimes, when you put a non-magnetic material like brass near a really strong magnetic field, it can show a tiny temporary magnetic effect—like, if you hold a powerful neodymium magnet an inch away from a thick stack of RA brass foil, you might feel a faint pull. But that’s not the same as being magnetic. That’s just the magnetic field inducing a tiny, temporary current in the brass, and the diamagnetic response creating a super small force. It’s nothing like a ferromagnetic material sticking, and it goes away the second you move the magnet. For all practical purposes, our RA brass foil is non-magnetic, and that’s what you need to know.
Now, why does this matter for our supply? As someone who’s been in the RA brass foil game for over 15 years, I can tell you that we’ve built our reputation on consistency. We don’t cut corners on alloy composition to undercut competitors. Every batch of RA brass foil we roll goes through testing to confirm it’s non-magnetic, because we know that if it’s not, our customers will have problems. That’s why we get repeat orders from aerospace teams, electrical manufacturers, and artists—they can count on our foil to behave exactly as advertised, no surprises.
I’ve also seen people mix up RA brass with other types of brass, like naval brass or cartridge brass. Those can have small amounts of iron added for strength, but standard RA brass is copper and zinc with no extra ferrous metals. That’s the standard we stick to because it’s the sweet spot for thin foil applications: it’s malleable enough to roll into super thin sheets, corrosion-resistant, and non-magnetic.
Let’s talk about a few real-world examples of where RA brass foil’s non-magnetic property is non-negotiable. In the automotive industry, modern electric vehicles use a ton of thin brass for battery tabs and bus bars. Magnetic materials near these tabs would cause unwanted resistance, which reduces the car’s range. EV manufacturers specifically specify non-magnetic brass for these parts, and our RA brass foil is a go-to for that. In medical devices, like pacemakers or diagnostic equipment, magnetism can interfere with sensitive electronics—so brass foil is the preferred material for parts that need to be near those devices, and we test every batch to make sure it’s not magnetic.
Another common use case: custom craft projects, like those metal embossing or resin inlay works. A lot of makers use brass foil for adding metallic accents to art, and if it were magnetic, it would mess up things like magnetic embossing tools, or even stick to metal molds while you’re working. Our customers in the craft space love that our foil is non-magnetic, so they can use it without worrying about those headaches.
Now, let’s address a few myths I’ve heard over the years. Some people think all metals are magnetic, which is totally wrong—only a handful are, and brass isn’t one of them. Others think that the thickness of the foil affects magnetism, but that’s not true either. Even a super thick sheet of RA brass will still be non-magnetic, because the base alloy doesn’t have the right elements to be ferromagnetic. Thickness might affect that tiny induced magnetism I mentioned earlier, but not the inherent non-magnetic property.
So, to circle back to the original question: Is RA Brass Foil magnetic? For the stuff we supply, the answer is a clear no. But if you’re looking at a different brand or a cheaper brass product, it might be—always ask for a non-magnetic test certificate if that’s a requirement for your project. That’s a service we offer, by the way—we can send test results for any batch of RA brass foil to show it’s non-magnetic, so you don’t have to take our word for it.
At the end of the day, this question boils down to understanding what you need your material to do. If magnetism is a problem for your project, non-magnetic RA brass foil is the way to go. We’ve been supplying this foil to customers for years, and the consistency is something we never sacrifice. If you’re working on a project and need to confirm if our RA brass foil will fit your needs, or you’re ready to place an order, feel free to reach out to our team to chat through your requirements. We can walk you through alloy specs, thickness options, and even send sample strips to test yourself before you commit to a full order. Don’t guess on magnetism—get the facts straight, and get the right material for your project.
Coil and Sheet References
- ASM International. (2006). Alloy Phase Diagrams: Copper-Zinc. ASM Handbook, Vol. 2.
- Nondestructive Testing Resource Center. (2021). Magnetic Properties of Non-Ferrous Alloys.
- Copper Development Association. (2019). Brass Foil Specifications for Electrical Applications.
- The World Steel Association. (2020). Ferromagnetism in Common Metal Alloys.
Civen Metal Material (Shanghai) Co., Ltd.
Address: Workshop 2-2, No.1888 Xiechun Road, Jiading District, Shanghai, 201804, P.R.China
E-mail: sales@civen.cn
WebSite: https://www.civenmetal.com/
