— Avoid “perfect” sharp internal corners: specify radii ≥ the diameter of a feasible end mill.
— Unify chamfers, e.g., 0.5×45°, to reduce tool changes.
— Design deep pockets with depth/diameter ≤ 3–5.
— Specify threads with standard and pitch, not just “M6.”
— Provide STEP/Parasolid + a PDF drawing with dimensions.
This discipline lets platforms like https://www.sppcncmachining.com launch the order without endless email ping-pong.