ABGUL
Parametric three-dimensional models to order

Writing a CNC machining brief

Model, material, stock, critical dimensions and inspection: what makes a clear machining brief.

ABGUL · · CNC · Materials

Geometry and revision

Send the current file and identify its revision. For multiple parts, provide a list and quantities. Highlight required dimensions on the drawing. Resolve model/drawing conflicts before manufacturing rather than leaving them to interpretation.

Material and surfaces

Specify material grade, permitted substitutions or a ban on substitutions, surface requirements and post-machining treatment. For customer-supplied stock, agree on dimensions and suitability. “Metal” or “plastic” alone is not a precise specification.

Tool access

Review deep pockets, thin walls and inside corners. A cutter has its own shape and size, so not every feature is reachable in one pass or from one side. Mark which geometry can change: an agreed adjustment may simplify manufacturing.

Acceptance criteria

Agree on which dimensions are inspected and how. Requirements should reflect part function. For assemblies, identify mating parts and whether a trial piece is needed. Keep the agreed brief with the file revision so repeat orders are unambiguous.

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