Neodymium Magnets: The Complete Guide
Neodymium magnets (NdFeB) are the strongest type of permanent magnet commercially available — up to 18 times more powerful than ferrite magnets of the same size. Made from an alloy of neodymium, iron, and boron, they’re the default choice for electric motors, sensors, holding applications, and consumer electronics wherever high magnetic performance needs to fit in a small footprint.
Radial Magnets stocks neodymium magnets in standard shapes and grades for same-day shipping, and manufactures custom sizes, tolerances, and true radial magnetization for OEM and engineering programs. Search stocked inventory or start a custom quote if you don’t see what you need below.
What Is a Neodymium Magnet?
A neodymium magnet is a permanent magnet made from Nd₂Fe₁₄B — an alloy of neodymium, iron, and boron arranged in a tetragonal crystal structure. That structure gives the material exceptionally high magnetocrystalline anisotropy, which is the technical reason neodymium magnets resist demagnetization so well and pack more magnetic energy into less material than any other commercial magnet type.
Neodymium magnets are a category of rare earth magnet — the other common rare earth type is samarium cobalt (SmCo), which trades some strength for better high-temperature stability. NdFeB magnets are manufactured in two ways:
- Sintered NdFeB — pressed and heat-treated from powdered alloy, then machined to final shape. This is the vast majority of neodymium magnets in commercial and industrial use, including everything Radial Magnets stocks.
- Bonded NdFeB — powdered alloy mixed with a polymer binder and injection-molded. Lower strength than sintered, but allows complex geometries and thinner cross-sections.
How Strong Are Neodymium Magnets? Grades Explained
Neodymium magnet strength is specified by grade — a number from N35 up to N52 that corresponds to the magnet’s maximum energy product (BHmax), measured in MGOe. Higher numbers mean a stronger magnet for the same volume, but with trade-offs in temperature resistance and brittleness.
| Grade | BHmax (MGOe) | Typical Use Case |
|---|---|---|
| N35 | 33–36 | General purpose, cost-sensitive designs |
| N42 | 40–43 | Common default for motors and holding |
| N45 | 43–46 | Higher force in the same envelope |
| N48 | 46–49 | Space-constrained high-force designs |
| N52 | 50–53 | Maximum strength at room temperature |
Grade alone doesn’t tell the whole story for engineering applications — intrinsic coercivity (HcJ) determines how well a magnet resists demagnetization at elevated temperature, which matters more than room-temperature BHmax in motors, automotive, and industrial-automation environments. See the full Neodymium Magnet Grade Chart for Br, HcJ, and BHmax by grade, and the NdFeB Temperature Classes guide for how N, M, H, SH, UH, EH, and AH temperature suffixes affect real-world performance.
Shapes and Types of Neodymium Magnets
Neodymium magnets are manufactured in most standard geometries:
- Disc and rod magnets — the most common stock shape, used in holding, sensing, and hobbyist applications
- Block and bar magnets — used in motors, speakers, and linear assemblies
- Ring magnets — including true radial magnetized rings, where the poles are arranged radially around the circumference rather than approximated from arc segments — Radial Magnets’ core specialty and a meaningful performance difference in motor and sensor rotor designs
- Pot (cup) magnets — a neodymium core assembled into a steel cup for concentrated holding force
- Arc and segment magnets — curved sections used in motor rotors and stators
- Sphere and specialty shapes
Browse all stocked neodymium shapes or see True Radial Magnets specifically.
Coatings: Why Neodymium Magnets Need Corrosion Protection
Bare neodymium alloy corrodes quickly in ambient humidity. Nearly all commercial NdFeB magnets are coated:
- Nickel-Copper-Nickel (Ni-Cu-Ni) — the industry-standard coating, durable and cost-effective for most indoor and general environments
- Zinc — better galvanic compatibility in some assemblies
- Epoxy — added corrosion and chemical resistance for harsher or outdoor environments
- Gold, silver, and specialty coatings — cosmetic or application-specific requirements
See the full Magnet Coatings Compared guide for selection criteria, and Epoxy-Coated Neodymium Magnets for that option specifically.
What Are Neodymium Magnets Used For?
Neodymium magnets’ combination of strength and small size makes them the default choice across a wide range of industries:
- Electric motors — BLDC and PMSM rotors in everything from cordless tools to EV traction motors (how magnets work in electric motors)
- Sensors — Hall-effect, TMR, and AMR position and speed sensing (sensor magnets guide)
- Holding and latching — pot magnets, door and cabinet latches, magnetic mounts
- Audio — speaker and headphone drivers
- Medical devices — MRI components, surgical tools, wearable devices
- Renewable energy — generator magnets in wind turbines
- Consumer electronics — laptop and phone latching mechanisms, wireless charging
Neodymium vs. Other Magnet Materials
| Material | Relative Strength | Max Operating Temp | Cost | Best For |
|---|---|---|---|---|
| Neodymium (NdFeB) | Highest | Up to ~200°C (grade-dependent) | Moderate | Motors, sensors, compact high-force designs |
| Samarium Cobalt (SmCo) | High | Up to ~350°C | High | High-temperature, harsh-environment applications |
| Alnico | Moderate | Up to ~540°C | Moderate | Very high-temp, stable-field applications (sensors, meters) |
| Ceramic (Ferrite) | Lowest | Up to ~250°C | Lowest | Cost-sensitive, high-volume, low-force applications |
For the full breakdown, see A Comprehensive Comparison of Magnet Types.
Handling and Safety
Neodymium magnets above roughly 1″ in size can pinch skin, shatter on collision with each other or with steel, and pose a serious ingestion hazard if swallowed (especially in multiples). Never ship or handle industrial-strength neodymium magnets without following basic precautions — see the full Magnet Safety Warning & Handling Instructions before working with unfamiliar sizes or grades.
Buying Neodymium Magnets: Stock vs. Custom
Need a standard size fast? Search our stocked inventory by dimension, grade, or SKU — 10M+ magnets on hand across both coasts with same-day shipping by 2PM EST.
Need a custom size, tolerance, or magnetization pattern? Submit a drawing through the RFQ Builder or use our Magnet Designer to spec dimensions and get instant pricing.
Buying in volume? Submit a Bulk RFQ with your BOM or part list for one consolidated quote, or ask about fixed-rate pricing and blanket orders for production programs.
Need PPAP, material certs, or compliance documentation? Visit the Compliance Document Center.
Frequently Asked Questions
What’s the difference between neodymium and rare earth magnets?
Neodymium (NdFeB) magnets are one type of rare earth magnet — the other is samarium cobalt (SmCo). “Rare earth magnet” refers to the broader category; neodymium is the specific alloy and the most widely used of the two.
How strong is an N52 neodymium magnet?
N52 is currently the highest commercially available grade, with a maximum energy product (BHmax) of 50–53 MGOe — roughly 50% stronger than a standard N35 magnet of the same size. See the full grade chart for a side-by-side comparison.
Do neodymium magnets lose their strength over time?
Under normal conditions, neodymium magnets lose magnetic strength extremely slowly — well under 1% over a decade. Strength loss accelerates sharply if the magnet is exposed to temperatures above its rated operating limit, physical damage, or a strongly opposing magnetic field. See Why Magnets Lose Strength for the full explanation.
Are neodymium magnets safe?
In normal industrial and engineering use, yes — but larger magnets can pinch skin, shatter violently on impact, and are a serious swallowing hazard, especially for children. Review our safety guide before handling unfamiliar sizes.
Can neodymium magnets be magnetized in custom patterns?
Yes. Beyond simple axial magnetization, neodymium magnets can be magnetized diametrically, radially, or in multipole patterns for motor and sensor applications. See Magnetization Directions Explained and Radial vs. Diametric vs. Segmented Magnetization.
Related Resources
- Neodymium Magnet Grade Chart
- NdFeB Temperature Classes Explained
- Magnet Coatings Compared
- Magnet Material Comparison
- Submit an Engineered Magnet RFQ
Radial Magnets stocks over 10 million NdFeB magnets in the U.S. across standard grades and coercivity classes, including true radially magnetized rings. Request a quote or contact us to discuss your application.
