How can you clearly communicate your magnet requirements to a supplier? What information is essential to receive an accurate quotation and lead time?
If you’ve ever experienced unclear pricing, repeated back-and-forth communication, or unexpected delays in magnet sourcing, you’re not alone.
In many cases, these issues are not caused by incomplete or unclear requirement definitions at an early stage.
In practice, defining a magnet sourcing request can be divided into two key aspects:
- Technical specifications of the magnet
- Project-related requirements such as lead time and quantity
From a technical perspective, several core parameters must be clearly defined, including:
Magnetic performance
- Shape and dimensions
- Magnetization direction
- Surface coating
Whenever possible, providing a technical drawing is highly recommended, as it significantly reduces misunderstandings and speeds up the quotation process.
In the following sections, we will use NdFeB permanent magnets as an example to explain each of these parameters in detail.
1. Magnetic Performance Requirements
Magnet grade is one of the most critical parameters when sourcing NdFeB magnets.
However, different suppliers may define the same grade slightly differently, with variations in performance ranges.
To avoid misunderstandings, both parties should clearly specify key magnetic properties, especially:
- Remanence (Br)
- Intrinsic coercivity (Hcj)
This ensures alignment beyond the nominal grade (e.g., N35, N52).
If the buyer is not familiar with magnet grades, alternative indicators can be provided, such as:
- Surface magnetic field
- Pull force
- Magnetic flux or magnetic moment
Depending on the application environment, additional parameters may also need to be defined:
- Temperature coefficients of Br and Hcj
- High-temperature performance requirements
For projects with strict performance targets (e.g., magnetic flux), it is recommended to define measurement methods and equipment in advance to ensure consistent evaluation standards.
2. Shape, Dimensions and Magnetization Direction
Clearly defining the geometry of the magnet is essential for accurate quotation and production.
For simple shapes, basic dimensions and tolerances should be specified, for example:
- Ø6.0 mm (+0.03 / -0.03)
For more complex geometries, additional requirements should be clearly defined, such as:
- Profile tolerance
- Angles (e.g., 30° ±1°)
Providing a technical drawing is strongly recommended, as it significantly reduces communication errors.
In addition to geometry, magnetization details must also be specified, including:
- Magnetization direction (orientation of N/S poles)
- Magnetization type (axial, radial, or multi-pole)
- Magnetization angle (if applicable)
3. Surface Coating Requirements
Surface treatment is essential for protecting NdFeB magnets from corrosion and environmental damage.
The buyer should clearly define:
- Coating method (e.g., electroplating, chemical plating, electrophoresis, vapor deposition)
- Coating material (e.g., Zn, Ni-Cu-Ni, epoxy, aluminum)
- Coating thickness
If corrosion resistance is critical, additional testing requirements should also be specified:
- Salt spray test conditions
- Duration of exposure
- Acceptance criteria
4. Additional Requirements
Depending on the project, other requirements may also need to be clarified, including:
- Appearance standards
- Additional testing (e.g., aging tests, reliability tests)
- Packaging requirements
- Transportation conditions
Although these factors are sometimes overlooked, they can significantly impact product consistency, delivery reliability, and overall cost.
5. Lead Time Considerations
Lead time is another critical factor in magnet sourcing and is mainly influenced by product type, tooling requirements, and production scheduling.
5.1 Standard vs. Customized Products
For standard NdFeB magnets, suppliers may maintain semi-finished stock (magnet blanks) with common grades and dimensions.
In such cases, lead time can be relatively short, as production mainly involves machining and coating.
For customized products, however, the situation is different.
Many non-standard shapes require dedicated tooling (molds).
If suitable tooling is not available, additional time is required for mold development, which can extend the overall lead time.
In practice, the geometry of the magnet is often a key factor influencing delivery time.
5.2 Production Scheduling
Even when all technical requirements are clearly defined, lead time is still affected by the supplier’s production schedule and order backlog.
During periods of high demand, production queues may extend to several weeks or even months.
5.3 Practical Recommendation
To ensure smooth project execution, it is recommended to place orders early for time-sensitive projects, confirm tooling availability at the initial stage, communicate clearly about urgency and delivery expectations
For urgent projects, early communication with suppliers can help identify possible solutions, such as priority scheduling and partial delivery arrangements
Whether you are at an early design stage, working with detailed specifications, or facing an urgent request, click to submit your inquiry.
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