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How to Review First Article Samples for Metal Parts

A practical first-article inspection checklist for OEM metal parts, covering drawing dimensions, fit, finish, function, and next actions.

How to Review First Article Samples for Metal Parts

First article review is where many custom metal part projects become real. A sample may look good at first glance, but the buyer still needs to check whether the part matches the drawing, fits the assembly, and supports the intended production route.

This guide gives buyers a simple way to review samples for MIM, powder metallurgy, and other OEM metal parts without turning the process into an engineering lecture. The goal is to catch issues early and move toward stable production with fewer surprises.

Coordinate measuring machine used for first-article inspection
First article review becomes easier when the sample, the drawing, and the inspection tools are aligned.

Start with the drawing

The sample should always be checked against the drawing first. That sounds basic, but it is the quickest way to avoid missing an issue that later becomes expensive. Confirm the overall size, critical features, hole positions, thickness, and any dimensions that affect assembly or function.

Check the surfaces that matter

Not every surface carries the same weight. Some parts can tolerate cosmetic variation in hidden areas but need cleaner treatment on visible or functional faces. Buyers should separate the surfaces that matter for appearance, wear, sealing, sliding, or contact from the ones that are not critical.

Review fit, Not just appearance

A sample can look polished and still fail in assembly. Check how the part sits in mating components, whether holes and edges behave as expected, and whether the part supports the intended motion, lock function, or load path. This is especially important for gears, pivots, valve-adjacent parts, precision mechanisms and other components where the sample must work inside an assembly.

Compare the sample against the intended process

A useful first article review should also tell the buyer whether the process route still makes sense. If the part needs repeated machining, heavy correction, or awkward secondary steps, the supplier should revisit whether MIM, PM, or another route is the best fit.

Density measurement equipment used during sample review
Process choice and sample review belong together, not in separate conversations.
Real SINTS precision small metal components used as a first-article review reference
First-article review follows the drawing and assembly function. SINTS component examples illustrate the types of geometry and features to inspect.
Plain and flanged bushing references
Structural parts often need sample review focused on fit and contact behavior.

A practical sample checklist

  • overall dimensions and critical tolerances
  • assembly fit and functional movement
  • surface finish on visible or contact areas
  • material or heat-treatment expectations
  • need for machining, polishing, or plating
  • packaging and handling condition

What to ask the supplier after review

If the sample is close but not yet right, ask the supplier which issues are geometry-related, which are process-related, and which can be solved with secondary operations. That keeps the conversation practical and helps the project move toward a better version of the same part instead of starting over.

Conclusion

First article review should be simple, disciplined, and tied to the part's real use. When buyers focus on drawing, fit, finish, and process fit together, the sample becomes a useful step toward stable production rather than just a checkpoint.

Have a drawing to discuss?

Send the drawing, sample results and open issues to our engineering team. We review the evidence against the agreed specification and project context.

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Frequently Asked Questions

Practical answers for OEM sourcing and engineering teams.

What should I check on first articles?

Critical dimensions, material certificate, hardness, density and surface finish against the drawing.

Which reports should I request?

Request the dimensional, material, hardness, density, metallographic or other reports that are defined by the drawing, control plan or customer program; not every project needs every document.

How do I close a PPAP?

Follow the customer-specific PPAP requirement and agreed control plan. Required evidence can include dimensional results, material/process records, capability data, samples and formal customer approval.

What if samples are out of tolerance?

Review the root cause with the supplier, agree the corrective action, and re-sample or re-inspect as required before repeat production.