A sample is more than something to hold
First samples let you assess both the part and the proposed manufacturing approach against agreed requirements. On a new job, drawing interpretation, workholding and acceptance criteria may all be tested together. Appearance or a successful trial assembly alone may not be enough.
The scope should suit the project. There is no single sample quantity or report that fits every part. Agree what the specification and risks require. If a particular first-article inspection standard is needed, identify it explicitly.
Start with the right revision
The sample and its report should identify the same part number and drawing revision. Resolve any mismatch before accepting the results. Material and finishing condition should also be traceable to the sample.
Approving an uncoated sample does not approve every dimension after coating. State which stage of manufacture the inspection represents. Later processes can change dimensions and surface behaviour.
Combine measurement with functional checks
Check dimensional and geometric requirements using suitable methods. Where assembly or functional testing is needed, define the conditions. A part fitting once does not prove that every tolerance is met; passing dimensional inspection does not prove suitability in every operating condition either.
Agree the datums and measurement approach for critical features. Results taken from different references can appear contradictory. Sharing the reporting requirements before machining is much easier than arguing about two incompatible reports afterwards.
Make the release decision explicit
Record the part, revision, sample identity and decision. If a deviation is accepted, define its scope and the quantity covered. The manufacturer should not treat an unresolved deviation as accepted.
When changes are requested, say whether series production must wait. A new drawing must prevent work continuing unintentionally to the old revision. The production inspection plan remains in place after sample approval; one accepted sample is not a blanket certificate for the rest of the order.
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