What Temperature Do Neodymium Magnets Lose Magnetism?

When you just finished a 3D print. You embedded some strong little magnets inside, expecting the finished piece to snap onto your metal workbench like it was possessed.

But instead? It slides right off.

What temperature neodymium magnets lose magnetism isn’t as straightforward as a single number. There’s a range. And if you don’t know the specifics for your magnet grade, you’re basically gambling with your project.

In this article, as a professional custom neodymium magnets manufacturer, let me break this down so you never have to learn this lesson the hard way.

The Short Answer (For The Impatient)

Standard neodymium magnets start losing strength above 80°C (176°F) . That loss is temporary if you cool them back down. But push them too far? Permanent damage.

And at the Curie temperature (roughly 310°C to 400°C), all magnetism is gone. Poof. No coming back.

But that’s just scratching the surface. Let me show you exactly what happens at each temperature range.

Temporary vs. Permanent Loss: What’s Actually Happening Inside The Magnet

Think of your magnet like a crowded room full of people all facing the same direction. That’s your magnetic alignment.

When you heat it up, those “people” start getting restless. They move around more. Some start turning the wrong way.

• Temporary Loss (>80°C) : For every 1°C rise in temperature, a standard neodymium magnet loses roughly 0.11% of its magnetic strength. But here’s the good news – once it cools back to room temperature, it returns to full strength. I’ve tested this myself. It’s fully reversible.
• Irreversible Loss (80°C to 230°C) : This is where things get dicey. If you exceed your magnet’s specific maximum operating temperature for too long, the internal structure actually degrades. When it cools down? It won’t regain its full strength. Ever.

Pro Tip: That 0.11% loss per degree adds up fast. At 150°C, you’re looking at roughly 7-8% temporary loss. But if you cross that grade’s threshold, that loss becomes permanent.

Maximum Operating Temperatures By Grade (Bookmark This)

Not all neodymium magnets are created equal. Manufacturers assign different temperature ratings based on the specific grade. Here’s the breakdown you need:

One thing to watch out for: higher strength grades like N50 and N52 actually have lower maximum operating temperatures – sometimes as low as 60°C. So that super strong magnet you bought? It might be less heat-resistant than a standard N42. Trade-offs, right?

The Curie Temperature: Where Magnets Go To Die

Here’s where what temperature neodymium magnets lose magnetism becomes absolute.

At the Curie temperature, thermal agitation completely destroys the magnetic alignment of the material. Think of it like melting ice – once it’s water, it’s not turning back into an ice cube on its own.

For standard neodymium magnets, the Curie temperature falls between 310°C and 370°C (590°F to 698°F) .

Even after cooling? Zero magnetic properties. You’d need a ridiculously strong external field to remagnetize it. And honestly? It’s never quite the same.

How Shape Affects Maximum Operating Temperature

This is where things get interesting.

You’d think maximum operating temperature is a material property, right? Water boils at 100°C whether it’s in a tall glass or a wide bowl.

Magnets? Not that simple.

The shape of your magnet directly impacts how hot it can get before losing performance. Engineers call this the “permeance coefficient” (or Pc). Here’s the rule of thumb:

• Tall, narrow magnets (like a cylinder where height > diameter) = higher temperature resistance
• Thin, wide magnets (like a flat disc) = lower temperature resistance

Let me give you a real example. A standard N42 disc magnet that’s 1/2″ diameter x 1/8″ thick? Its actual maximum operating temperature is only about 60°C – even though the grade says 80°C.

But a 1/4″ cylinder where the diameter equals the height? That same N42 material can handle up to 140°C before seeing irreversible losses.

Mind blown, right?

I learned this the hard way when I kept wondering why my thin disc magnets kept failing in moderately warm environments. Now I use the Magnet Calculator to check the Pc value for every design.

Low Temperatures? Magnets Actually Love The Cold

Here’s something counterintuitive.

While we’re focused on what temperature neodymium magnets lose magnetism from heat, cold temperatures actually make them stronger.

Neodymium magnets operate best at lower temperatures. They continue getting stronger as the temperature drops, all the way down to about -130°C.

At that point, something weird happens. The preferred magnetization direction shifts by about 30 degrees, reducing performance by roughly 15%. But here’s the kicker – when you warm it back up to room temperature, it returns to normal.

I’ve submerged neodymium magnets in liquid nitrogen (-196°C) just to test this. They still had about 85-90% of their original strength. And after warming up? Good as new.

One warning though: don’t thermal shock them. Moving a magnet from really cold to really hot quickly can cause them to crack or break. Let them warm up naturally.

Can You Remagnetize A Weakened Magnet?

Yes, it’s possible to remagnetize neodymium magnets that have been weakened by heat. But here’s the bad news – they won’t be as strong as they were originally.

The more you exceeded the maximum operating temperature, the weaker they’ll be after remagnetization. And if you hit the Curie temperature? Don’t bother.

Most magnet suppliers (including the ones I trust) don’t even offer remagnetization services for demagnetized magnets. It’s usually more cost-effective to just buy new ones.

Real-World Examples: Where This Actually Matters

Let me give you two scenarios where understanding what temperature neodymium magnets lose magnetism saves your project.

Scenario 1: 3D Printing With Embedded Magnets

I see people do this all the time. They print with ASA or ABS using a bed temperature of 100-110°C, pop in some standard N-grade magnets, and wonder why their print has zero holding power afterward.

Those cheap Amazon magnets? Most start losing strength in the 80-100°C range. By the time your print finishes, permanent damage is already done.

Solution? Either use high-temperature grade magnets (SH or higher) or print at lower bed temps. I personally print with Atomic ASA at 70°C bed temp – warping is minimal and my magnets stay happy.

Scenario 2: Steam Cleaning Pipelines

If you’re using magnetic separators in a pipeline that gets cleaned with steam (typically above 100°C), standard neodymium magnets will get permanently compromised. Most users have no idea their magnetic separation performance has dropped off a cliff.

For these applications, you need actual high-temperature rated magnets. Or better yet, switch to Samarium Cobalt (SmCo) magnets for extreme environments – they handle up to 300°C.

The Bottom Line

So what temperature do neodymium magnets lose magnetism?

Standard N-grade magnets start losing strength at 80°C (176°F) with fully reversible loss. Permanent damage occurs above your grade’s maximum operating temperature (ranging from 100°C to 230°C depending on grade). Total demagnetization happens at the Curie temperature between 310°C and 400°C.

But remember – shape matters. Thin, wide magnets fail earlier. Tall, narrow magnets resist heat better. And cold temperatures? They make your magnets stronger until about -130°C.

Here’s my advice: always check your magnet’s grade and its shape before exposing it to heat. Use a permeance coefficient calculator if you want to be precise. And when in doubt, buy a higher temperature grade than you think you need.

Because nothing sucks more than finishing a project, going to use it, and realizing your magnets are now just expensive metal spacers.

Now go check the specs on those magnets you just bought. You might be surprised.