What to include in a CNC machining enquiry

Bring the drawing and open questions into the discussion.

A useful CNC enquiry explains both the shape of the component and the conditions it must meet. The CAD model provides geometry; the drawing and order notes describe the requirements that cannot be inferred from shape alone.

Give the model and drawing a consistent part number and revision. If you send an assembly reference, identify which items are included in the machining scope and which are provided only to explain the fit.

A housing may need clearance for a board, a connector opening and a cover interface. A shaft may have one diameter that controls the assembly fit. Identify those relationships rather than relying on the recipient to infer the function of every feature.

Mark the dimensions, datum references and acceptance requirements that matter to the finished assembly. Include mating-part information where it explains an interface. If a requirement is still open, describe the question and keep it separate from confirmed specifications.

Name the material grade and required condition. An alloy designation without the relevant temper or heat-treatment requirement may leave the material specification incomplete for your application.

Include the surface treatment and identify visible faces, protected areas and contact surfaces. State where dimensions apply to the finished part. Avoid leaving a treatment note in a separate email if it changes the drawing requirements.

Quantity and delivery expectations are part of the enquiry. Distinguish an initial sample quantity from a later batch, and identify any approval step needed before the next stage.

Add the records, identification and packing requirements expected by your receiving team. These should be visible while the quotation scope is being reviewed, rather than introduced after the parts have been made.

Check that the files describe the same revision and that no older drawing is included by accident. List unresolved points in a short note so they can be addressed during review.

A complete enquiry does not require a long email. It requires a consistent set of files and a concise statement of what the finished component must satisfy.

Include the current revision, material, quantity and any inspection or finishing requirements when you send your project.