• How should you communicate your requirements with magnetic material sales representatives
• Which key details must be clearly defined to obtain an accurate quotation and lead time?
If you have these questions when purchasing magnetic materials, then this article will be very helpful for you.
Clearly defining magnet procurement requirements mainly consists of two parts:
1. The basic requirements for the magnet.
2. The project lead time requirements
Basic Magnet Requirements
To clearly define a magnet procurement requirement, the following key aspects must be specified: performance, dimensions, magnetization direction, and surface coating. Providing technical drawings is highly recommended. Below is an example based on NdFeB magnets.
1. Performance Requirements
This refers to the magnet grade.
Since different suppliers may define the same grade with varying performance ranges, it is recommended to specify remanence (Br) and intrinsic coercivity (Hcj) to avoid deviations. If the grade is unknown, provide reference parameters such as surface field, pull force, magnetic flux, or magnetic moment.
Depending on the operating environment, additional parameters such as temperature coefficients of Br and Hcj may also be required.
For applications with defined flux requirements, testing methods and equipment should be agreed upon as acceptance criteria.
2. Dimensions and Magnetization Direction
The magnet’s shape and dimensions must be clearly specified, e.g., 6.0 mm (+0.03 / -0.03). For simple parts, provide length, width, height, and tolerances. For complex geometries, additional requirements such as profile tolerance and angles (e.g., 30° ±1°) should be clearly defined. Supplying detailed drawings is recommended.
In addition, specify the magnetic orientation (N/S poles), magnetization type (single-pole or multi-pole), and magnetization angle.
3. Surface Treatment Requirements
The buyer should specify the required surface treatment, including coating method (e.g., electroplating, electroless plating, electrophoresis, vapor deposition), coating material (e.g., Zn, Ni, Cu, Al, epoxy), and coating thickness.
If salt spray or other tests are required, the test conditions, duration, and acceptance criteria should be clearly defined.
4. Other Requirements
Such as appearance standards, additional testing requirements (e.g., aging tests), packaging, and transportation requirements.
Lead Time
Most suppliers maintain stock of magnet blanks with standard performance grades. The product shape largely determines the lead time.
Customized products typically require dedicated tooling. If suitable tooling is not available, additional time will be needed for mold fabrication, extending the lead time.
Overall lead time can sometimes be compressed, but may not fully meet the buyer’s ideal schedule. For urgent orders, early placement is strongly recommended.
