“I need a strong magnet. How much does it cost, and how soon can you deliver?”

For a magnet supplier, this information alone is usually insufficient to provide an accurate quotation. Even magnets with identical dimensions can differ in manufacturing cost and lead time depending on the material, magnetic properties, tolerances, coating, magnetization requirements, and order quantity.

What information should you prepare before requesting a quotation? If you do not know which magnet grade you need, how should you explain your requirements to the supplier? Using sintered neodymium (NdFeB) permanent magnets as an example, this guide walks you through six practical steps.

1. Start with the Application: Where Will the Magnet Be Used, and What Must It Do?

The supplier needs to understand whether the magnet will be used for holding and fixing, motor drives, sensing, magnetic coupling, magnetic separation, or another purpose. Each application has different selection priorities.

For example, the actual pull force in a holding application depends not only on the magnet itself but also on the material, thickness, and surface condition of the steel being attracted, as well as any air gap. A required pull force should therefore always be stated together with the specific operating conditions.

If you are unsure which grade to choose, clearly describing the operating conditions and target function is more useful than guessing a grade.

2. Define the Technical Specifications: Material, Dimensions, Magnetization, and Surface Treatment

2.1 Material and Magnetic Properties: Specify More Than Just a Grade

If material selection has already been completed, specify the magnet material and grade, such as sintered NdFeB and the corresponding grade designation.

To reduce differences in interpretation between suppliers, critical projects should also specify the required ranges for relevant magnetic properties, including:

- Remanence, Br;

- Intrinsic coercivity, Hcj;

- Maximum energy product, (BH)max;

- Temperature coefficients and magnetic performance requirements after exposure to elevated temperatures, where necessary.

The grade designation is a starting point for communication. The agreed magnetic properties and acceptance criteria provide the basis for subsequent delivery and inspection.

2.2 Shape, Dimensions, and Tolerances: Drawings Are More Reliable Than Verbal Descriptions

Simple products can be described using basic dimensions, for example:

- Block magnets: length × width × thickness;

- Disc or cylindrical magnets: diameter × thickness or height;

- Ring magnets: outer diameter × inner diameter × thickness.

For arc magnets, countersunk magnets, stepped magnets, or other custom shapes, provide an engineering drawing showing the relevant angles, radii, hole positions, and tolerances.

For example:

- Diameter: 6 mm — insufficient if a specific tolerance is required;

- Diameter: 6.00 ±0.03 mm — clearly specified.

The following points should also be confirmed:

- Whether the drawing dimensions refer to the uncoated magnet or the finished, coated product;

- Which dimensions are critical to assembly;

- Whether flatness, parallelism, or profile tolerances are required;

- Whether chamfers or rounded edges are needed, including their dimensions;

- The drawing revision, units, and applicable notes.

Tolerances should match the actual functional requirements. Excessively tight tolerances can increase machining and inspection costs and may also affect production yield and lead time. For dimensions that do not affect assembly or performance, discuss more economical tolerances with the supplier.

2.3 Magnetization Direction and Pole Pattern: Identical Shapes Can Serve Different Functions

Even when the material and dimensions are identical, different magnetization directions can produce very different results in the application.

When requesting a quotation, specify:

- Whether the magnets should be supplied magnetized;

- Whether magnetization should be along the length, width, or thickness;

- Whether ring or arc magnets require axial, radial, or another magnetization pattern;

- Whether multipole magnetization is required, including the number of poles, pole pitch, and pole pattern;

- Whether the north or south pole must be marked;

- Whether an angular tolerance for the magnetization direction is required.

2.4 Surface Treatment: Specify Both the Coating and the Operating Environment

Common surface treatments for sintered NdFeB magnets include Ni-Cu-Ni plating, zinc plating, and epoxy coating. Selection should account for corrosion resistance, dimensional fit, and subsequent assembly requirements, as well as appearance.

If salt spray testing is required, specifying “pass a 48-hour salt spray test” is not enough. The test type, applicable standard, test duration, and post-test acceptance criteria should also be agreed upon.

The same test duration does not necessarily mean the same test conditions or acceptance criteria.

3. Agree on Acceptance Criteria in Advance: How Will Compliance Be Verified?

For projects with special quality requirements, you can also agree on a sampling plan, batch traceability information, and inspection reports to be supplied with the shipment.

4. Specify Order Quantities: Request Separate Quotations for Samples, Pilot Runs, and Mass Production

Quantity is an important factor in pricing and production scheduling.

If you ask only for a unit price without specifying the required quantity, the supplier can usually provide only an initial price indication. State the requirements for each stage separately:

- Sample quantity;

- Initial pilot-run quantity;

- Quantity per mass-production order;

- Estimated annual demand;

- Whether deliveries need to be split into multiple shipments.

5. Clarify Lead Times: Distinguish Production Completion from Arrival

A “two-week lead time” might refer to production completion, dispatch, or arrival. Without an agreed starting point and delivery milestone, misunderstandings can disrupt project schedules.

When requesting a quotation, specify:

- The date by which samples must arrive;

- The expected time needed for sample approval;

- The required arrival date for the first mass-production batch;

- Whether partial deliveries are acceptable;

- The delivery destination and shipping method.

Also confirm when the lead time begins—for example, after technical specifications are finalized, the order is confirmed, or the agreed payment is received.

6. Include Packaging and Shipping Requirements in Your Purchase Specifications

Magnets are brittle, and strong magnets can snap together during handling and assembly. Packaging should therefore be selected according to the product dimensions, magnetic strength, coating, and the customer’s unpacking process.

Confirm the following requirements in advance:

- Whether individual separation is required to prevent contact and collisions;

- Whether magnetic pole directions need to be marked;

- Whether each inner pack should contain a fixed quantity;

- Whether labels must show product numbers, batch information, or quantities;

- Whether magnetic shielding packaging and transport-related testing are required;

- Whether moisture protection, corrosion protection, or special cleanliness requirements apply.

If the magnets will be used in automated feeding systems or assembled in a specific sequence, explain the required packaging orientation and arrangement in advance.

7. What Does a Clear Magnet RFQ Look Like?

This example illustrates how to organize RFQ information. Specific parameters should be determined based on the actual application.