Welcome to Eclipse Magnetics — your trusted experts in magnetic solutions for industrial, engineering, and precision applications.
Choosing the right magnet is critical to achieving maximum performance, safety, and efficiency in your project. This guide explains everything you need to know about magnet materials, field operation, and the most effective magnet types.
⚙️ How to Choose the Right Magnet Material
When selecting a magnet for your application, consider the following key performance factors:
✅ Flux requirement – How strong does the magnetic field need to be?
🔥 Maximum operating temperature – What temperatures will it face?
🧪 Corrosion resistance – Will the magnet be exposed to moisture or chemicals?
📈 Magnetic stability – Does it need to maintain its magnetism over time?
⚖️ Size and weight limitations – Is space or weight a design constraint?
These factors help determine which magnetic material is best suited for your application — whether it’s for holding, clamping, lifting, or actuation.
💪 Magnet Strength & Flux Density Comparison
Below is a comparison of the four main magnet materials, showing their relative strength and magnetic energy.
| 🧲 Magnet Material | Max Energy Product (MGOe) | Max Energy (kJ/m³) | Flux Density (Gauss) |
|---|---|---|---|
| Ferrite | 3.3 | 26 | 1,050 |
| Alnico | 5.2 | 42 | 1,300 |
| Samarium Cobalt | 26 | 208 | 3,500 |
| Neodymium (NdFeB) | 35 | 279 | 4,500 |
💡 Neodymium magnets are the most powerful available — ideal where high magnetic flux density or limited space is required.
🌡️ Temperature Performance
Every magnet has a limit. Understanding temperature effects is key to maintaining magnetic performance and avoiding demagnetisation.
| Magnet Type | Max Operating Temp (°C) | Performance at Sub-Zero | Reversible Effect (20°C–150°C) |
|---|---|---|---|
| Ferrite | 250°C | Minimal loss below -60°C | -0.19% per °C |
| Alnico | 540°C | Minimal to none | -0.02% per °C |
| Samarium Cobalt | 300°C | Stable | -0.03% per °C |
| Neodymium* | 80°C* (up to 230°C grades) | Stable down to -196°C | -0.12% per °C |
🔧 Note: Higher-grade neodymium magnets are available for applications up to 230°C.
🧼 Corrosion Resistance & Demagnetisation Stability
In harsh environments, corrosion resistance and stability are vital. Below is a comparison of how different materials perform.
| Magnet Material | Corrosion Resistance (Uncoated) | Resistance to Demagnetisation |
|---|---|---|
| Ferrite | Excellent | High |
| Alnico | Fair | Low |
| Samarium Cobalt | Excellent | Very High |
| Neodymium | Poor (usually nickel/zinc coated) | Very High |
💡 Samarium Cobalt offers the best all-round performance for temperature and corrosion stability, while Neodymium delivers the highest magnetic strength.
🔩 Magnetic Field Operation Explained
1️⃣ Single Pole Operation (Across an Air Gap)
Used when a depth of field is required for attraction or switching.
Examples include bar magnets, disc magnets, and ring magnets.
-
Field travels across an air gap.
-
Strength diminishes with distance.
-
Ideal for actuation and sensing applications.
🧲 Example: Bar magnet with a north-to-south field across an air gap.
2️⃣ Two Pole Operation (Clamping, Holding & Lifting)
Perfect for direct contact applications, such as lifting or gripping ferromagnetic materials.
Examples include horseshoe, button, and pot magnets.
-
Field does not travel far but is concentrated and strong.
-
Excellent for holding and clamping.
🧲 Example: Horseshoe magnet providing a concentrated flux path between poles.
⚙️ Pot Magnets – Compact Power & Precision
Pot magnets combine strength and control by encasing the magnet within a steel shell, focusing the field onto one active face.
✅ Key Benefits
-
No stray magnetic flux — enclosed circuit design
-
Protected from demagnetising effects
-
Machinable for custom integration
-
Can be inserted into steel housings without performance loss
⚠️ Note: Pot magnets have a shallower field than bar magnets but deliver superior grip on contact.
🔘 Button Magnets
-
North and south poles on a single face
-
Compact and strong for tight space applications
-
Ideal for small-scale clamping and fixing
🧲 Horseshoe Magnets
-
Classic U-shape for maximum magnetic strength
-
Excellent for lifting, holding, and educational demonstrations
-
Provides intense, concentrated magnetic field between poles
📞 Need Expert Advice or a Custom Magnet Design?
At Eclipse Magnetics, we design and manufacture bespoke magnetic solutions for industrial and commercial use.
Whether you need a custom pot magnet, lifting magnet, or precision neodymium assembly, our team is here to help.
📞 Call us: +44 (0)114 225 0600
📧 Email us: info@eclipsemagnetics.com
🏭 Eclipse Magnetics – Innovative Magnetic Solutions
With over 100 years of magnetic expertise, Eclipse Magnetics leads the industry in precision magnetic engineering.
From neodymium magnets to custom assemblies, we deliver strength, reliability, and innovation across every application.