What to send for a CNC machining quote: a buyer’s checklist
Prepare drawings, materials, quantities and inspection requirements so CNC suppliers can quote the same scope.
Start with a consistent drawing package
A useful quotation request lets each supplier evaluate the same part and the same requirements. Send a readable 2D drawing together with a STEP model when available. Put the part number and revision on both, and identify which document governs if they disagree. A screenshot can help explain a question, but should not be the only definition of a production part.
State the material and quantity clearly
Specify the material grade instead of only writing aluminium or stainless steel. If an equivalent grade is acceptable, ask the supplier to name it before quoting. Separate prototype quantity, first production quantity and possible repeat demand. Treat a forecast as a forecast, rather than promising orders that are not confirmed.
Identify what matters for fit and function
Point out mating surfaces, threads, datum references, critical dimensions and finish requirements. Do not apply a tighter tolerance everywhere simply to express a wish for quality: discuss the function and how the dimension will be inspected. If a requirement is missing, request clarification instead of letting different suppliers make different assumptions.
Compare the complete quotation scope
Ask whether material, programming or setup, tooling, finishing, inspection, packaging and freight are included. Confirm currency, delivery destination and any separately charged items. Lead time should state its starting point, such as drawing approval or material availability. A low unit price is difficult to compare when these items are not aligned.
Copy this enquiry checklist
Part number and revision; drawing and model files; material grade; prototype and batch quantities; critical tolerances; finish and masking requirements; inspection documents; requested delivery date and destination; questions or acceptable alternatives. Send only files you are authorised to share. For confidential work, discuss confidentiality requirements before sharing drawings.