Neodymium magnets are the strongest permanent magnets.
This complete guide covers neodymium magnet basics for beginning buyers.
Learn about their composition, grades, coatings, and more.
If you’re new to neodymium magnet buying, start here.
Let’s get started.
Overview
Neodymium magnets are a type of permanent magnets made from an alloy of rare earth elements: neodymium, iron, and boron.
- They have the strongest magnetic force of any magnet available commercially.
They are usually your first choice, when you need to pick a type of magnets for your applications.
Use rare earth magnets to build motors, and reduce the volume and weight of motors of the same power by more than 30%.
Help synchronous motors – built with rare earth magnets – to replace the most energy-consuming asynchronous motors, the power saving rate can reach 12% – 15%.
Properties
Generally speaking, manufacturers produce neodymium magnets with an alloy of of rare-earth elements: neodymium, iron, and boron.
- This type of magnets represented by the chemical symbol NdFeB.
- Each element plays a crucial role in the performance of the magnet.
Neodymium (Nd)
This rare earth element is responsible for the high magnetic strength of the magnet.
- It’s the key ingredient that makes neodymium magnets the strongest type of permanent magnet.
Iron (Fe)
Iron provides the magnetic moment or ‘magnetism’ of the material.
- However, it’s also prone to oxidation (rust).
- This is why neodymium magnets are typically coated or plated with another material to prevent corrosion.
Boron (B)
Boron is a small, light element that helps to ‘lock in’ the magnetic orientation of the material, increasing the coercivity or resistance to demagnetization.
It also contributes to the formation of the crystalline phase that gives neodymium magnets their strong magnetic properties.
The exact composition of a neodymium magnet can vary slightly, and other elements like dysprosium or praseodymium can be added to improve certain properties like heat resistance. However, the fundamental structure and performance of the magnet are derived from the combination of neodymium, iron, and boron.
Common Names
When searching for neodymium magnets, you may come across other names used to describe these powerful magnets.
Some common alternate names include:
- NdFeB magnets – Using the chemical symbols for neodymium (Nd), iron (Fe) and boron (B), which are the materials for producing neodymium magnets.
- NIB magnets – Another abbreviation using the element symbols.
- Neo magnets – A shortened version of “neodymium”.
- Rare earth magnets – Neodymium is a rare earth metal, hence this is also a descriptive name.
- Strong magnets – This name refers to their high magnetic field strength compared to other magnet types.
- Super magnets – Highlighting their magnetic strength superiority over traditional magnets.
So, you can check the keywords in product listings or descriptions.
- If you see terms like “strong magnets”, “NdFeB”, “NIB”, “neo”, or “rare earth”, these are simply different names for neodymium magnets.
- They all indicate the same high-performance permanent magnet material.
Knowing the alternative names helps ensure you can find neodymium magnets even when they are not referred to by the full name.
Features
Below are some of the most important features that you should consider neodymium magnets.
Strongest magnetic pull force
Neodymium magnets have the highest magnetic strength of any permanent magnet material commercially available today.
Their unique crystalline structure allows for magnetic field intensities far greater than other types of magnets.
This exceptional magnetic power means they can outperform other magnets in a wide range of applications.
Their high strength-to-size ratio allows miniaturization and weight reduction for things like motors, sensors, speakers, and more.
High energy for size
One key advantage of neodymium magnets is their exceptionally high energy density. This means they can produce extremely strong magnetic fields from a very small volume of material.
The compact nature of neodymium allows for miniaturized magnets that weigh less, take up less space, and use fewer raw materials. For a given application, neodymium magnets can be made much smaller and lighter compared to other magnet types.
Their energy efficiency makes them perfect for applications where weight and size need to be minimized. Small neodymium magnets can outperform much larger magnets of different materials.
This enables innovations like ever-smaller sensors, motors, and electronics that incorporate very powerful yet minute magnets. For portable devices, electric vehicles, wind turbines, and other uses where weight matters, the high energy density of neodymium is ideal.
So when seeking the most magnetic “punch” from the smallest possible magnet, neodymium’s unmatched energy density makes it the ultimate choice for compact, lightweight yet potent magnetic systems.
Resistance to demagnetization
Neodymium magnets have a very high coercivity, which is a measure of how resistant a magnet is to becoming demagnetized. Their strong magnetic fields are able to withstand external influences that could potentially knock the magnets out of alignment and cause loss of magnetism.
This high coercivity comes from neodymium’s unique crystalline structure which makes it difficult for the aligned magnetic domains in the material to be disrupted. Even very strong conflicting magnetic fields have difficulty altering the set magnetic orientation.
The more coercive a magnet is, the more stable the magnetic field. This resistance to demagnetization allows neodymium to reliably maintain its powerful magnetic properties over time and under challenging conditions.
Applications that generate heat, vibration, shock or stray magnetic fields benefit from neodymium’s exceptional coercivity. The magnets retain their full strength despite strong external forces acting upon them. This makes them ideal for miniaturized devices and unstable environments.
Cost-effectiveness
Despite having the strongest magnetic fields commercially available, neodymium magnets are surprisingly inexpensive. Mass production and ongoing innovations in manufacturing have made neodymium affordable for many different buyers and applications.
Compared to older technologies like Samarium Cobalt or Alnico, neodymium magnets offer superior performance at a fraction of the price. Their low cost makes them accessible and opens up new possibilities for DIY, hobbyists, educators, and small business owners.
Major industrial and technology companies also benefit from the competitive pricing of neodymium. Now high-performance magnetic systems can be produced efficiently and economically. The price-to-performance ratio makes neodymium an ideal choice for a huge range of consumer, commercial, and industrial products.
So if you assumed the strongest magnets would be costly, think again – neodymium delivers unmatched field strength at a price point that brings high performance magnets within reach. Whether you’re a professional engineer or weekend tinkerer, neodymium’s combination of low cost and superb quality makes it the number one choice for top-end magnetic properties on a budget.
Easy to Find
The popularity and mass production of neodymium magnets means they are readily available.
- You can easily find neodymium magnets from local stores, web stores and ecommerce sites.
Manufacturers and sellers offer neodymium magnets in many standard and custom shapes:
- For example, discs, blocks, rings, spheres, tiles, rods, and more.
They also come in a broad range of sizes from tiny magnets that weigh less than a gram to large magnets over several pounds.
Neodymium magnets are graded by their maximum operating temperatures and magnetic properties. Common grades like N35, N42, and N52 are extensively produced and easily sourced. Higher performance grades are also available for specialized uses.
With so many shapes, sizes, and grades on the market, it’s simple to obtain neodymium magnets tailored to your exact specifications and application requirements. Production volume and accessibility means finding the right neodymium magnets is just a web search away for both retail and commercial buyers.
Two Types
When it comes to neodymium magnets, you generally have two options: stock magnets or custom magnets.
Stock neodymium magnets
They are pre-made and ready to ship.
Advantages:
- Ready made and available to ship quickly
- Lower costs compared to custom magnets
- Easy to purchase in small quantities
- Range of common sizes and strengths already in production
Disadvantages:
- Limited to existing shapes, sizes and magnetic properties
- May not meet specialized requirements
- Quantity discounts only available for large orders
Custom neodymium magnets
They allow you to specify the exact dimensions, tolerances, coating, and magnetic properties you require.
Advantages:
- Can be made to meet specialized requirements
- Customizable dimensions, shapes, and tolerances
- Ability to specify magnetic strength and properties
- Optimized for specific applications and products
- Higher level of quality control
Disadvantages:
- Higher costs due to custom fabrication
- Longer lead times for production
- Minimum order quantities may be required
- More complex design and specification process
- Testing and prototyping may add time and cost
Knowing the pros and cons of each can help you decide whether stock or custom neodymium magnets are the best fit for your needs.
How to Choose
Custom magnets make sense when you need a very specific magnet for a product or application.
And stock magnets are ideal for more common use cases where you can select from existing options.
If you are a regular or average user, stock neodymium magnets are likely a better choice.
They strike an ideal balance of performance, cost, and convenience.
3 Production Techniques
There are 3 production techniques to obtain the shapes of neodymium magnets.
Sintering
Sintered neodymium magnets are made by mixing the magnet powder with a binder and then compressing the mixture into a die.
The die is then heated in a furnace to fuse the magnet powder together.
Sintering is the most common production technique for neodymium magnets and offers the highest magnetic properties.
Pros:
- High magnetic properties
- Excellent temperature stability
- Ideal for high-performance applications
Cons:
- Limited to simple geometries
- Higher cost compared to other production techniques
- Longer lead time
Bonding
Bonded neodymium magnets are made by mixing the magnet powder with a binder and then molding the mixture into the desired shape.
The mixture is then cured at room temperature or low temperature.
Bonding is a cost-effective option for producing magnets with complex shapes.
Pros:
- Can produce magnets with complex shapes
- Cost-effective compared to sintering
- Shorter lead time
Cons:
- Lower magnetic properties compared to sintered magnets
- Limited temperature stability
- Not ideal for high-performance applications
Hot Pressing
Hot pressed neodymium magnets are made by heating the magnet powder to a high temperature and then applying pressure to the mixture in a die.
The process results in a magnet with high magnetic properties and excellent temperature stability.
Pros:
- High magnetic properties
- Excellent temperature stability
- Ideal for high-performance applications
Cons:
- Limited to simple geometries
- Higher cost compared to other production techniques
- Longer lead time
Grades
Neodymium magnets are assigned different grades based on their magnetic strength and maximum operating temperature.
- Common grades you will see are N35, N42, N45, N48, N50, and N52.
- The first letter “N” designates the material type, standing for neodymium.
First Letter
The first letter of a magnet’s grade designation is a handy code telling you the magnetic material.
This helps when comparing the properties of different magnet types.
- “N” stands for neodymium magnets (NdFeB)
- “C” is for ceramic or ferrite magnets
- “A” is for Alnico magnets
- “S” indicates samarium cobalt magnets (SmCo)
- “Y” denotes yttrium magnets
Checking this first letter quickly reveals the magnet composition and helps differentiate grades from different materials.
It’s an easy shorthand that you can use to interpret grade information when researching and comparing different types of magnets.
Number
The number in a neodymium magnet grade – like N48 – refers to its Maximum Energy Product or “BHmax”.
- This represents the magnet material’s maximum magnetic flux density, measured in megaGauss-Oersteds or MGOe.
- A higher number grade indicates a higher BHmax and stronger magnetism.
- So, a N52 magnet has a higher BHmax than a lower grade like N35.
The BHmax occurs at the “knee” of the magnet’s demagnetization curve.
- The point where the magnetic field reaches its peak density before dropping off.
- The grade number represents this optimal magnetic energy.
- For most basic uses, an N35 or N42 grade neodymium magnet can provide a good balance of strength and cost.
In short, the number rating reflects the neodymium grade’s Maximum Energy Product or magnetic field strength ceiling.
Last Letter
The last letter of neodymium magnet grades indicates the temperature resistance of the magnet.
- If there are no letters following the grade, then the magnet is standard temperature neodymium.
- Standard neodymium magnets maintain their listed flux density up to 80°C (176°F).
Other letters like “NH” and “SH” designate specialty neodymium grades.
- No letter – 80°C / 176°F
- M – 100°C / 212 °F
- H – 120°C / 248°F
- SH – 150°C / 302°F
- UH – 180°C / 356°F
- EH – 200°C / 392°F
- AH – 230°C / 446 °F
Higher grades like N52 are used where the maximum field strength is critical.
So in short, the grade guides the magnetic power and temperature resistance.
Consider your application and environment to determine what grade suits your particular needs as a buyer.
Temperature Ratings
When buying neodymium magnets, it’s important to consider temperature ratings.
If your applications are close or even within a heat source, then you must pick the grade with the sufficient temperature resistance.
- Neodymium magnets become weaker when exposed to higher temperatures.
- Excess heat can cause them to lose magnetic strength completely.
- Make sure you check 2 temperature ratings.
Maximum Working Temperature
This is the highest temperature a neodymium magnet can withstand before it starts losing its magnetic strength.
- A neodymium magnet loses 0.11% of its magnetism for every 1 degree Celsius rise in temperature.
- If a magnet gets hotter than this, it will become weaker.
- Below this point, they keep their full strength.
Every grade of neodymium magnets has a temperature range.
- The maximum working temperature is the upper limit – beyond this, the magnetism gets impacted.
- If you go over the maximum, the magnet won’t completely die, but its strength will decrease.
- It’s the hot zone where permanent damage starts happening.
In simple terms, this threshold represents the hottest a magnet can tolerate before magnetic decline sets in.
- The maximum working temperature lets you know when extra heat will start sapping a magnet’s power.
- Staying below this level keeps magnets operating at full capacity.
Curie Temperature
Once a magnet has been heated up beyond its specific Curie temperature, it won’t act like a magnet anymore.
- The high temperature removes the magnetism.
- It can no longer attract or repel other magnets or ferromagnetic materials.
- And this change is permanent.
In everyday terms, the Curie temperature is the cutoff point where magnets demagnetize and can no longer stick to or attract metals.
- Heating magnets over their Curie temperature ruins their magnetic powers forever.
- Knowing the Curie point helps prevent permanent damage when working with magnets.
If your applications require the magnets to withstand higher temperatures, then consider other types of magnets.
Below is a list of the approximate Maximum Working Temperature (MWT) and Curie Temperature (CT) for 3 other types of magnets.
- AlNiCo magnets: MWT = 525°C / 977°F; CT = 800°C / 1,472°F.
- Samarium cobalt (SmCo) magnets: MWT = 310°C / 590°F; CT = 700°C / 1,292°F.
- Ferrite (Ceramic) Magnets: MWT = 250°C / 482°F – 450°C / 842°F.
Coatings
We need to apply coatings to neodymium magnets.
There are two main groups of coatings:
Cost-effective coatings
- Zinc – Basic corrosion protection, silver appearance
- Nickel – Moderate corrosion resistance, shiny metallic look
- Epoxy – Smooth plastic coating, chips/peels over time
- Rubber – Impact/vibration dampening, grip enhancement
- PVC – Glossy vinyl coating, prone to wear
These coatings are affordable.
They are good starter solutions but have limitations in adhesion, durability, and corrosion resistance.
Performance coatings
- PTFE – Extreme non-stick properties, temperature resistance
- Parylene – Impermeable barrier coating, excellent durability
- Gold – Exceptional corrosion protection, electrical conductivity
- Silver – High chemical resistance, thermal conductivity
These coatings provide specialized properties and enhanced durability for demanding applications. They outperform basic coatings but also cost more.
Consider the coating benefits needed versus budget when selecting magnet protection.
Superior coatings maximize longevity and functionality but may not suit every buyer’s requirements.
Safety
The incredible strength of neodymium magnets comes with safety considerations:
Magnet safety
Neodymium magnets are brittle and can crack or shatter if they slam together with force. Handle carefully to avoid damage.
- Don’t allow magnets to snap together from a distance. The rapid collision can weaken or break them.
- Properly cushion and separate magnets during storage and shipping to prevent forceful contacts.
- Be aware the pull force can cause injury to hands/fingers if magnets abruptly attract.
User safety
Neodymium magnets can violently pinchy skin, causing bruises or blood blisters. Keep away from fingers and other body parts.
- Magnets flying together can shatter and send shards at high speed. Wear eye protection when handling.
- Keep a safe distance when handling large neodymium magnets. Their pull force can draw metal objects toward you.
- Pacemakers, electronics, magnetic media like credit cards can be affected. Maintain some distance.
With proper care and precaution, neodymium magnets can be used safely.
But their sheer power warrants extra vigilance to prevent personal injuries or magnet damage.
Shipping regulations
When purchasing large neodymium magnets online, it’s important to be aware of air shipping restrictions.
- Air safety regulations strictly limit the exterior magnetic field allowed on commercial flights.
- Air transport doesn’t ship magnet packages with detected magnetic field over a certain value at a certain distance.
Before ordering large neodymium magnets, always consult with the supplier about shipping methods.
Air transport limitations present unique challenges for delivery time.
- Your supplier may have to send you by sea or by road.
- So, you should be prepared for when purchasing big magnets.
Single-sided Magnets
A single-sided magnet is a magnet that only has magnetic force on one side.
- All magnets have two poles – a north pole and south pole.
- In some uses, having the magnetism on just one side is needed.
To make a single-sided magnet, one side of the magnet is covered with an iron sheet.
- This iron shielding blocks the magnetism on that side.
- It reflects the magnetic force to the uncovered side, concentrating the magnetism there.
So technically, true single-sided magnets don’t exist.
There is still magnetism on both sides, but one side’s magnetism is shielded by iron.
Single-sided magnets are made by combining powerful neodymium magnets, usually disk shaped, with arc-shaped iron sheets covering one side.
The iron shields one pole’s magnetism to create strong, focused magnetism from just one side.
Single-sided magnets have many applications across different industries:
- In printing and packaging, they are widely used for gift boxes, mobile phone boxes, tobacco and alcohol boxes, MP3 cases, moon cake boxes, and more. The single-sided magnets allow secure closures for these packaging products.
- For leather goods like bags, briefcases, travel bags, phone cases, and wallets, single-sided magnets enable secure closures while maintaining a slim profile.
- In stationery, single-sided magnets can be found in notebooks, whiteboard fasteners, folders, name badges, and more. The focused magnetism on one side allows convenient mounting and fastening.
In summary, the focused magnetism of single-sided magnets makes them useful whenever a slim magnetic mounting or closure is needed on boxes, bags, stationery, and other products.
The one-sided magnetism saves space compared to regular magnets.
Conclusion
This beginner’s guide covered the basics of neodymium magnets.
Let us know if you have any other questions.
Email us if you need help buying neodymium magnets.