Approving a custom magnetic assembly sample should be a documented engineering decision, not just a quick visual check. The sample needs to be evaluated against a defined drawing, functional requirements, and acceptance method. The steps below are a practical review framework for engineering and procurement teams; the specific tests and limits must come from the application’s approved requirements.
1. Confirm the sample’s identity and revision
Record the part number, drawing revision, bill of materials or approved material callouts, sample date, and any supplier reference or lot information available. Clarify whether the sample represents the intended production configuration or is an early prototype with known differences. Do not approve an unidentified sample or assume that a visually similar part matches the current release.
2. Review critical dimensions against the released drawing
Identify which dimensions control fit or function and how they will be measured. Use the drawing’s datums, tolerances, and agreed measurement approach rather than estimating from photographs or comparing by eye. Record the measured results for the characteristics that matter. If a dimension is missing, ambiguous, or conflicts with another file, resolve the drawing before treating the sample as an approval reference.
3. Check mechanical fit in the real interface
Where practical, trial the sample with the mating components or a representative fixture. Check mounting points, clearances, orientation, fasteners, cable or sensor paths, and access for installation or service. Record any shimming, adjustment, or rework needed to make it fit. An approval should not hide a workaround that is absent from the released design.
4. Verify magnetization and magnetic criteria as specified
When the drawing or specification defines magnetization direction, pole pattern, polarity, field, or force, compare the sample using the agreed method. The test record should identify the fixture, measurement location, gap or spacing, mating material, orientation, and any other conditions needed to interpret the result. If the acceptance method or limit has not been agreed, define it with the application engineer before using a subjective hand test as a substitute.
5. Check materials, finish, and assembly details
Compare visible construction and surface condition with the released documents, but do not use appearance alone to verify a magnet grade, alloy, coating, or internal component. If material certificates, process records, or other documents are required by the purchase specification, include them in the approval package. Nibboh’s public factory information lists engineering, machining, coating, and magnetizing among its processes and notes that custom shapes, grades, and surface treatments are available; confirm the precise requirements for each design.
6. Run a repeatable functional check
Test the sample in the configuration that reflects its intended use, following a written sequence and the agreed load or operating conditions. Keep the setup consistent between samples and record pass/fail criteria, observations, and any unexpected interaction with nearby parts. If the function depends on a controller, sensor, or housing, include that interface in the test plan rather than evaluating the magnet in isolation.
7. Log deviations and decide their disposition
For every difference from the released requirement, record what was observed, the affected revision or characteristic, and the decision owner. Choose a clear disposition: correct and resubmit, revise the design, or accept a documented deviation where your quality process permits it. Avoid informal “approved with comments” language that leaves the production team unsure which requirements were waived.
8. Complete the production handoff before sign-off
Make sure the approved sample is tied to a controlled drawing and configuration. Agree how production checks will reference the critical dimensions and magnetic criteria, what records are required, how packaging or identification should work, and how later changes will be reviewed. Ask the supplier to confirm the scope and limits of the production inspection plan; do not assume a sample approval automatically defines every future lot check.
Make the approval specific and traceable
A useful sign-off names the exact part and revision, lists the checks completed, records unresolved items or approved deviations, and identifies who accepted the result. Keep the inspection notes and sample reference with the released documents. This gives engineering, purchasing, and the supplier one shared basis for any later review.
Nibboh describes customized magnetic assemblies for project requirements. Explore the magnetic component range or send the approved drawing and requirements through the contact page to discuss a specific design.