How to Tell if a Magnet is Neodymium Magnet? 5 Simple Tests

Have you ever held a tiny silver disc that felt like it weighed 10x more than it should? And when you brought it near a fridge, it snapped into place with a force that almost caught your fingers?

Yeah. That’s probably a neodymium magnet.

But not every shiny silver magnet is neodymium. And if you’re buying magnets online (especially from marketplaces like AliExpress or Amazon), there’s a good chance you’re getting ripped off.

So how to tell if a magnet is neodymium without a fancy lab?

That’s exactly what I’m going to show you in this guide.

As a professional custom neodymium magnets manufacturer, I’ve personally tested hundreds of magnets over the past few years. Some were legit. Most were fake. And I’ve developed a handful of dead-simple methods to spot the real deal.

Let’s dive in.

Why Identifying Neodymium Magnets Matter?

Neodymium magnets (also called NdFeB or rare earth magnets) are the strongest permanent magnets on the planet. A coin-sized neodymium magnet can lift several pounds of metal.

They’re also expensive to manufacture. So shady sellers love to pass off weaker (and cheaper) magnets as high-grade neodymium.

In fact, based on my own testing, over 80% of “N52” magnets from AliExpress are actually grade N35 – which is about 50% weaker.

So if you don’t know how to tell what you’re holding, you’re probably overpaying.

Let’s fix that.

How to Tell if a Magnet is Neodymium?

I’m going to break this down into five tests you can do at home. No expensive lab equipment required.

1. The Strength Test (Most Reliable)

This is my go-to method.

Neodymium magnets are scary strong for their size. A 10mm disc can hold over 2kg of steel. Try that with a standard black ceramic magnet, and it’ll fall right off.

Here’s what to do:

Take your magnet and bring it near a steel surface (a fridge door works perfectly). If it’s neodymium, you’ll feel a strong pull from at least half an inch away.

Now try to pull it straight off.

Can’t do it without sliding? That’s a good sign.

Pro Tip: Compare it to a known ceramic magnet of the same size. The neodymium magnet will feel 5-10x stronger. I’m not exaggerating.

2. The Slide Test

Here’s something most people don’t realize:

You can’t pull two neodymium magnets straight apart.

Seriously – try it.

If you have two magnets that snap together face-to-face, try to pull them apart. If they come apart easily? They’re probably not neodymium.

Legit neodymium magnets are so strong that you have to slide them off the edge of one another. That’s the only safe way to separate them.

The bottom line? If you can snap two magnets together and pull them straight apart without sliding, they’re likely standard ferrite magnets.

3. The Appearance Test

Let’s talk about looks.

Neodymium magnets have a distinct silver-white metallic finish. But here’s the catch – they’re actually terrible at resisting corrosion.

That’s why manufacturers almost always plate them.

The most common plating is nickel-copper-nickel (a triple layer). This gives them that bright, shiny, almost chrome-like appearance.

What to look for:

• Color: Bright silver, not dull gray
• Texture: Smooth and dense – feels like real machined metal
• Weight: Surprisingly heavy for their size

One caveat: Some neodymium magnets come with other platings (gold, black epoxy, zinc). So appearance alone isn’t enough. But if it looks like a cheap black ceramic magnet? Definitely not neodymium.

4. The Brittleness Test

This one’s a bit dangerous, so be careful.

Neodymium magnets are made using a sintered crystalline structure. That’s a fancy way of saying they’re brittle – like glass.

If you drop a ceramic magnet on tile, it might bounce. If you drop a neodymium magnet? It can chip, crack, or even shatter into sharp pieces.

Here’s the common scenario:

You’re trying to separate two stuck magnets. They snap together unexpectedly. Crack. Now you’ve got a broken magnet and tiny sharp shards everywhere.

Bottom line: If your magnet chips like glass instead of bouncing like ceramic, it’s almost certainly neodymium.

5. The Pull-Force Meter Test (For Disputes)

Alright, this one’s for when you want to prove a seller sold you fake “N52” magnets.

I built a simple device using a kitchen scale and a steel plate. Cost me about $20.

Here’s how it works:

• 1. Get a digital kitchen scale (grams work fine)
• 2. Place a thick steel plate on top
• 3. Put your magnet on the steel plate
• 4. Slowly pull the magnet straight up and note the maximum weight reading

This gives you the magnet’s pull force.

Now here’s the magic:

If you have a known N35 magnet (the weakest neodymium grade) of the same size, compare the numbers. A genuine N52 magnet should be about 50% stronger.

In my testing, fake “N52” magnets almost always match N35 pull forces exactly. That’s how I’ve won multiple disputes on AliExpress.

What About Magnet Grades? (N35 vs N52)

I get this question all the time.

Neodymium magnets come in different grades – N35, N38, N42, N45, N48, N50, N52. The number represents magnetic strength. Higher number = stronger magnet.

N52 is the highest grade commercially available. It’s about 50% stronger than N35.

But here’s the problem:

Sellers know that “N52” sounds impressive. So they slap that label on N35 magnets all the time.

How to tell if a magnet is neodymium and also verify its grade?

Use the pull-force meter I just described. Measure your magnet’s pull force. Then compare it to published specs for that size and grade.

If the numbers don’t match? You’ve been had.

Real-World Example: My AliExpress Testing

Let me share some data from my own magnet inventory.

I ordered a batch of 10x10x10 mm “N52” magnets from AliExpress. When I tested them, the pull force was around 1,900 grams.

Then I tested legit N35 magnets of the exact same size. Pull force? Also around 1,900 grams.

Coincidence? Nope.

That’s a 50% difference from what N52 should deliver. I filed a dispute, showed my photo evidence, and got a partial refund.

The seller didn’t even argue.

Pro Tip: Always test a batch when you receive it. Even within the same order, I’ve seen pull force vary from 60g to over 180g. That’s a 3x difference. That doesn’t happen with quality manufacturing.

Common Myths About Neodymium Magnets

Let me clear up a few things I hear all the time.

“Neodymium magnets lose strength over time”

Not true. Rare earth magnets have excellent resistance to demagnetization. They won’t lose strength around other magnets or from being dropped.

However – heat is the enemy. Standard N-grade neodymium starts losing strength above 176°F (80°C). And above 590°F (310°C)? They demagnetize completely.

“All neodymium magnets are the same”

Definitely not. Manufacturing quality varies wildly. A sloppy sintering process leads to poor magnetic alignment and weaker magnets – even if the chemical composition is identical.

That’s why two “N52” magnets from different sellers can perform completely differently.

“You can machine neodymium magnets easily”

No. Just no.

Neodymium is brittle and prone to chipping. Machining generates heat, which can demagnetize the material. And if it gets too hot? The dust is toxic.

Bottom line: Don’t machine neodymium magnets. Buy the size you need.

Where to Buy Genuine Neodymium Magnets

Based on my experience, here’s what I recommend:

Reputable sources:

• K&J Magnetics (US-based, excellent quality)
• Imanes Osenc (China-based, flexible MOQ)
• Applied Magnets
• TotalElement

Be very careful with:

• AliExpress (assume everything is N35 unless proven otherwise)
• Random Amazon third-party sellers
• eBay deals that seem too good

My rule of thumb: If the price is 50% lower than everyone else, the grade is probably 50% lower too.

Quick Reference Checklist

Here’s a summary to help you answer how to tell if a magnet is neodymium in under 60 seconds:

Conclusion

So now you know exactly how to tell if a magnet is neodymium.

Let me recap the key takeaways:

1. Do the strength test first – if it’s not dramatically stronger than a ceramic magnet of the same size, it’s not neodymium.

2. Use the slide test – genuine neodymium magnets require sliding to separate.

3. Check the appearance – look for that bright silver, machine-cut finish.

4. Be careful with brittleness – neodymium chips like glass.

5. Build a pull-force meter if you want to prove grade discrepancies and win disputes.

I’ve personally used these methods to test hundreds of magnets. They work. And they’ve saved me from overpaying for fake “N52” magnets more times than I can count.

Now I want to hear from you:

Have you ever bought magnets online that turned out to be weaker than advertised? What happened?