1. Product Overview

The square hole speaker magnet is made from high-performance sintered NdFeB or ferrite materials, providing excellent magnetic properties and structural adaptability. Its central square hole is specifically designed to support voice coil positioning and enhance heat dissipation in speaker magnetic circuits, thereby improving acoustic response efficiency and system stability. This magnet is widely used in high-fidelity audio systems, Bluetooth speakers, multimedia sound systems, and TV speaker modules. Custom sizes, magnetic grades, and surface coating options are available, offering high energy density, low distortion, and reliable assembly performance.

2. Technical Parameters

Product Name: Square Hole Speaker Magnet
Magnet Grade: N42M (Br ≥13.5 KGs, Hcj ≥12 KOe)
Product Dimensions: Y12*7*3
Tolerance: Length ±0.05 mm, Width ±0.05 mm, Thickness ±0.05 mm
Operating Temperature: ≤ 100°C (High-temperature version available)
Density: ≥7.5 g/cm³
Surface Magnetic Field: 3200 ± 200 Gauss (Measured using TM-801 Gauss meter)
Magnetic Flux: 1.8 mWb (Measured with fluxmeter)

3. Manufacturing Process

Special-Shaped Cutting: Performed using dedicated non-standard wire-cutting equipment for non-square/non-circular geometric machining.

Grinding & Shaping: Used for complex structures and high-precision contour finishing to ensure dimensional and geometric tolerances.

4. Surface Treatment & Coating Technology 

To enhance corrosion resistance and appearance:

Default Plating: Triple-layer Ni-Cu-Ni (customizable).

Standard Thickness: Ni (3μm) + Cu (5μm) + Ni (4μm).

Optional Plating: Single-layer Zn (5μm) for cost-sensitive projects.

5. Appearance & Dimensional Inspection Standards

To ensure product quality consistency and reliability, all products undergo the following inspections:
- Manual Measurement with Micrometer/Caliper
- Visual Inspection (Light Intensity: 800–1200 lumens, Distance: 20–30 cm)
- 2D Optical Measurement (For irregular or non-standard geometries)

6. Reliability Testing

- Shock and Vibration Testing: Simulates handling and operational impact to ensure reliability in practical environments.
- High-Temperature Demagnetization Test: Validates stability of magnetic performance under elevated temperatures.
- Damp Heat Test: Exposes the magnet to high humidity to assess moisture resistance and corrosion durability.

7. Packaging Process & Instructions

We follow specialized packaging procedures tailored for magnetic materials:
- Eliminate substandard items based on appearance and dimensional checks
- Magnetize and neatly arrange qualified items
- Boxed in fixed quantities with custom labels as required
- Each box is vacuum-sealed with magnetic shielding plates and cushioning pads
- Small boxes are packed into cartons designed to resist moisture, shock, and magnetic interference
Custom packaging is available

8. Application Areas

- High Power Density Motor Systems: Axial flux motors; linear motor tracks
- Particle Accelerators and Research Devices: Synchrotron insertion devices; strong field lab magnets
- Medical Imaging and Treatment Devices: MRI superconducting shielding; proton beam control systems
- Quantum Technology Infrastructure: Ion trap quantum computers; superconducting quantum chips

9. Precautions

- Handling: NdFeB material is hard and brittle. Avoid dropping, collision, or chipping during handling.
- Safety: Strong magnetism. Avoid bending. Recommended to separate using a sliding motion to avoid pinching.
- Proper Installation: Identify polarity before installation to ensure correct device operation.
- Storage: Store in a dry, cool, and non-corrosive environment. Avoid exposure to acids and alkalis.
- Magnetic Isolation: Keep magnets away from hard drives, IC cards, pacemakers, and other sensitive electronics.

10. Customization & Services

- Customizable size, shape, and coating (layer count, thickness, color)
- Custom magnetization direction and strength
- Laser LOGO or serial number marking
- Tailored packaging solutions and suction force testing for special applications