N35 vs N40 Magnets: Key Differences, Uses, and Which One to Choose

You’re looking at two magnets that look exactly the same: same size, same shape, same coating. But one is labeled N35 and the other N40. Which one should you buy? Picking the wrong grade can mean wasted money or a project that just doesn’t hold up. N35 vs n40 magnets is a common dilemma, but the answer isn’t complicated.

In this guide, as a professional custom N35 magnets and N40 magnets manufacturer, I will break down the real difference in magnetic energy, pull force, cost, and temperature limits. You’ll learn exactly when N35 is good enough, why N40 might be worth the upgrade, and what to do if you need even more holding power. By the end, you’ll know which grade fits your project without any guesswork.

What Does the Number Mean?

Before we compare N35 and N40, you need to understand what the number stands for.

The “N” stands for neodymium. The number represents the maximum energy product of the magnet. That’s measured in MGOe (Megagauss-Oersteds). Basically, it tells you how much magnetic energy the material can hold.

• N35 = 35 MGOe
• N40 = 40 MGOe

The higher the number, the stronger the magnet. Simple enough, right?

But here’s the thing: a higher grade doesn’t always mean a better magnet for your specific use case. It depends on what you need. Let’s get into the specifics.

N35 vs N40 Magnets: The Key Differences

As you can see, N40 offers about 14% more magnetic energy than N35. That’s a real difference. But it’s not a night-and-day difference.

Let me explain what that means in the real world.

Strength and Pull Force

When people ask about N35 vs N40 magnets, they usually want to know one thing: How much stronger is N40?

The answer? N40 is noticeably stronger. But not twice as strong.

For example, a standard N35 disc magnet might have a pull force of around 5 pounds. The exact same magnet in N40 might have a pull force of around 5.7 pounds. That’s roughly a 14% boost.

Will you feel that difference? Yes, if you’re doing things like holding heavier objects or needing a stronger grip in a compact space.

But here’s the catch: size matters way more than grade.

A larger N35 magnet will easily outperform a smaller N40 magnet. So if you’re trying to decide between a bigger N35 and a smaller N40, the bigger N35 will usually win.

I personally recommend always starting with the size you need. Then choose the grade that fits your budget and performance requirements.

Gauss and Flux Density

Another spec you’ll see is the surface field, measured in Gauss.

N35 magnets typically have a surface field of around 11,700 to 12,100 Gauss. N40 magnets come in around 12,900 to 13,300 Gauss. Again, that’s a boost. But don’t get too hung up on these numbers.

What actually matters is how the magnet performs in your application. Higher Gauss means a stronger magnetic field close to the magnet. But in many real-world situations, you won’t notice a massive difference between N35 and N40 unless the magnet is working near its limit.

Temperature Tolerance: Both Are Similar

This is an important one.

Both N35 and N40 are standard neodymium grades. That means they have the same maximum operating temperature: 80°C (176°F).

If you expose either magnet to more heat than that, it will start to lose its magnetic strength permanently. That’s bad.

So if your project involves high heat, neither N35 nor N40 is the right choice. You’d need a grade with a temperature suffix like N35SH or N40SH. Those can handle up to 150°C.

But for normal indoor use? Both N35 and N40 are totally fine.

Cost and Availability

Let’s talk money.

N35 is the most widely produced neodymium grade on the market. It’s cheap. It’s everywhere. You can find it at craft stores, hardware stores, and online retailers without any trouble.

N40 is a bit less common. It’s more of a specialty grade. You’ll usually find it from magnet suppliers that sell to businesses and hobbyists. It costs more per magnet, but not by a huge amount.

Here’s my take: if you’re on a tight budget and need a bunch of magnets, N35 is the smart choice. If you need that little extra holding force and don’t mind paying a slight premium, N40 is worth it.

Common Applications of Each

Use Cases for N35 Magnets

N35 magnets are perfect for everyday projects. They’re strong enough for most tasks, and they won’t break the bank.

Here are some common uses:

• DIY crafts and model making
• Home organization and storage
• Magnetic closures for boxes and bags
• Fridge magnets
• Whiteboard and bulletin board magnets
• Toys and educational projects
• Light holding and mounting tasks

In my experience, N35 is the best starting point for beginners. It’s forgiving to work with. And you can buy a ton of them without spending too much money.

Use Cases for N40 Magnets

N40 is for when you need a bit more power in the same footprint.

For example, let’s say you’re building a magnetic latch for a wooden box. The space is tight. You can’t fit a bigger magnet. But the N35 version you tried isn’t strong enough. That’s when you step up to N40.

N40 is also a good choice for:

• Small magnetic sensors and actuators
• Custom fixtures and jigs
• Compact electronic devices
• Magnetic separators in lab or industrial settings
• Projects where every millimeter of space counts

Basically, choose N40 when you need a stronger pull but can’t increase the magnet size.

N35 vs N40 Magnets: Which Is Better for Your Project?

Now for the question you came here to answer. Should you go with N35 or N40?

Here’s a simple way to decide:

Choose N35 if:

• You’re working on a hobby project
• You need a large quantity of magnets
• Cost is your main concern
• The holding force isn’t critical
• You’re using magnets for crafts, displays, or basic closures

Choose N40 if:

• You need maximum holding force in a small size
• You can’t increase the magnet dimensions
• You want a performance boost without jumping to an expensive grade like N52
• The project is commercial or optimized for performance
• You’ve already tested N35 and it wasn’t enough

In many cases, N35 is all you need. But when you’re pushing the limits of space, N40 gives you that extra edge.

Is N40 Worth the Upgrade?

The short answer? Sometimes.

If you’re comparing a 10mm N35 disc to a 10mm N40 disc, the N40 will give you about 14% more pull force. That could be the difference between the magnet holding or not holding in certain situations.

But if the N35 already does the job, there’s no reason to upgrade. Save your money.

Here’s a rule I use: Upgrade only when performance demands it.

For example, in 2026, I worked on a small product prototype that needed a compact magnetic latch. The N35 version worked, but it was too weak for the spring-loaded lid. Switching to N40 solved the problem without redesigning the enclosure.

That’s the sweet spot for N40.

Let’s Not Forget N42 and N52

I get it. You’re comparing N35 and N40. But it’s worth mentioning that the neodymium magnet grade spectrum goes higher.

• N42 is the workhorse of industrial applications. It’s about 20% stronger than N35.
• N52 is one of the strongest grades you can buy. It’s powerful, but expensive.

Why does this matter? Because sometimes the real choice isn’t N35 vs N40. It might be N35 vs N42.

If you need significantly more strength, N42 might be a better investment than N40. It’s widely available and offers a better performance-to-cost ratio.

N40 sits in a bit of a middle ground. It’s stronger than N35, but not as common as N42. That doesn’t make it bad. It just means you should know exactly why you’re choosing it.

Factors That Affect Magnet Performance

Don’t get too caught up in the grade number. Several other factors affect how strong a magnet feels:

• Size and shape – Bigger magnets are always stronger.
• Magnet material – The grade only tells you part of the story.
• Coating – Nickel, epoxy, and other coatings can affect friction and durability.
• Air gap – Magnets lose strength rapidly as distance increases.
• Steel thickness – The magnet needs enough metal to “grab” onto.

I’ve seen people buy N52 magnets and complain that they’re weak. Then I find out they’re trying to hold something through a half-inch piece of wood. That’s not a magnet issue. That’s a physics issue.

So before you upgrade from N35 to N40, double-check your actual setup. Sometimes a better placement or a larger magnet solves the problem.

How to Test N35 vs N40 Magnets Yourself

If you’re still not sure, here’s a simple way to test both grades:

• 1. Buy the same size magnet in N35 and N40.
• 2. Set up a steel plate or metal surface.
• 3. Attach each magnet and add weight until it falls.
• 4. Compare the results.

You can also use a pull force tester if you want exact numbers. But for most projects, a simple test will tell you everything you need to know.

Pro Tip: Wear safety gloves when handling strong magnets. They can snap together and pinch your skin. Trust me, that hurts.

My Recommendation

Let me put it plainly.

For most hobbyists and DIYers, N35 is the right choice. It’s affordable, easy to find, and strong enough for 90% of projects.

For engineers, product designers, and anyone with a size constraint, N40 is worth considering. That extra 14% can make a real difference when you can’t go bigger.

The bottom line? Don’t overthink this.

Start with N35. If it works, you’re done. If it doesn’t, move up to N40. And if N40 still isn’t enough, skip straight to N42 or N52.

Simple as that.

Wrapping Up

Neodymium magnets are amazing. They pack a ton of power into a small package. And choosing the right grade makes all the difference.

N35 gives you solid, reliable performance at a great price. N40 gives you that extra boost when you need it most. Both have their place.

Just remember: the best magnet isn’t the highest grade. It’s the one that fits your project, your budget, and your performance needs.

So whether you’re building a craft project, a prototype, or a commercial product, you now have the info you need to make the right call. And if you’re still going back and forth, grab both grades and test them yourself. That’s the most reliable way to know.

Now go pick your magnets and get building. 🧲

Still weighing the decision? The N35 vs n40 magnets comparison doesn’t have to be complicated. Choose N35 for everyday use, choose N40 for that extra edge, and let your project tell you what it needs.