Magnet Testing & Quality Control
Magnet Testing & Quality Control
At Magnet Forever, we prioritize quality and reliability in every step of magnet production. High-performance NdFeB magnets and ferrite magnets undergo rigorous testing to ensure stable magnetic performance, dimensional accuracy, corrosion resistance, and long-term durability.
Q.C.Organization Chart
We have complete product quality control procedures.
In every link of production, we will conduct random inspections regularly to ensure the pass rate of the final product.
1. Magnetic Performance Testing
Key Tests:
| Test | Purpose | Description |
|---|---|---|
| Flux / Magnetic Field Measurement | Verify magnet strength | Measures the magnetic flux of the magnet using a gauss meter or Helmholtz coil. Ensures the magnet meets specified Br and BHmax values. |
| Coercivity (Hc & Hcj) Test | Resistance to demagnetization | Determines how well the magnet can withstand external or reverse magnetic fields without losing performance. |
| Magnetization Direction Verification | Correct pole orientation | Confirms that the magnet is magnetized in the correct direction (axial, radial, or multi-pole). |
| Demagnetization Curve (B-H Curve) | Energy performance | Shows the relationship between magnetic flux density (B) and applied field strength (H) to confirm maximum energy product (BHmax). |
Why it matters:
Magnetic testing ensures each magnet achieves its designed magnetic output, critical for applications like motors, speakers, sensors, and industrial assemblies.
2. Dimensional & Mechanical Testing
Key Tests:
| Test | Purpose | Description |
|---|---|---|
| Dimensional Inspection | Accuracy | Uses calipers, CMM (Coordinate Measuring Machine), or gauges to verify length, width, height, and hole positions. |
| Weight & Density Check | Consistency | Confirms uniform density, which affects magnet strength and stability. |
| Hardness / Compression Test | Structural integrity | Ensures magnets can withstand machining and handling without cracking. |
Why it matters:
Precise dimensions and mechanical stability are crucial to ensure the magnet fits and functions correctly in assemblies and devices.
3. Surface & Corrosion Testing
Key Tests:
| Test | Purpose | Description |
|---|---|---|
| Coating Thickness Measurement | Uniform protection | Confirms plating or epoxy coating meets specifications for corrosion resistance. |
| Adhesion & Salt Spray Test | Durability | Simulates long-term exposure to humidity and corrosive environments. |
| Visual & Microscopic Inspection | Detect defects | Checks for cracks, chips, or plating defects that could compromise performance. |
Why it matters:
Proper surface protection ensures long-term reliability of magnets, especially in humid or harsh environments.
4. Temperature & Environmental Testing
Key Tests:
| Test | Purpose | Description |
|---|---|---|
| High-Temperature Testing | Heat resistance | Tests magnet stability at elevated temperatures based on grade (M/H/SH/UH/EH). |
| Thermal Cycling | Long-term durability | Simulates repeated heating and cooling to ensure magnet properties remain stable. |
| Humidity & Moisture Test | Environmental resilience | Checks for oxidation, corrosion, and performance degradation in humid environments. |
Why it matters:
Magnets in motors, EV components, and industrial equipment must maintain performance under extreme temperatures and environmental conditions.
5. Magnetic Assembly Testing
Magnetic force uniformity: Confirms consistent pull or holding force.
Alignment check: Ensures correct magnetic field direction in assemblies.
Functional testing in devices: Optional testing in motors, speakers, or sensors for application-specific verification.
6. Quality Certification & Traceability
All magnets are 100% inspected before shipment.
Full batch traceability: chemical composition, sintering parameters, and inspection results recorded.
ISO 9001, IATF/TS16949, and ISO 14001 certified processes guarantee compliance with international quality standards.
✅ Summary
At Magnet Forever, every magnet undergoes comprehensive testing—from magnetic performance and dimensional accuracy to corrosion resistance and environmental stability. This ensures that our NdFeB and ferrite magnets deliver high performance, reliability, and long-term stability for motors, electro-acoustic devices, industrial applications, and more.