A better magnet enquiry starts with the right details.

The practical information that helps a supplier understand what your design needs.

Begin with the drawing.

A useful enquiry describes the finished part and the conditions it will work in. A drawing should identify the units, dimensions, tolerances and pole orientation. If you only have an early concept, explain that so the next step can be agreed.

The information to gather

1. Geometry: diameter, thickness, length, bore or arc dimensions as appropriate.
2. Magnetic requirements: material, grade if specified, magnetisation direction and the performance your engineer needs.
3. Working conditions: temperature range, moisture, exposure and the surrounding assembly.
4. Surface and fit: coating, finish, edge details and important tolerances.
5. Commercial requirements: sample quantity, production quantity, repeat usage and timing.
6. Acceptance: the inspection reports, sample tests and traceability the customer needs.

Agree what will be tested.

Dimensions and appearance alone do not establish magnetic performance. A suitable technical partner can help define measurements and a sample approval process. NPL publishes a service for measuring permanent-magnet materials, including NdFeB.

Keep confidential information controlled.

Start with a description of the requirement. Share proprietary drawings only after agreeing who may receive them and how they will be used.

Further reading: NPL: permanent-magnet measurements and Arnold: neodymium magnet materials.

This guide is an introduction. Final selection and acceptance criteria need to be agreed for your application.