DESIGN FOR MANUFACTURING / CNC MACHINING INSIGHTS
Thin walls can be essential to a part’s weight, clearance or enclosure space, but they need more context than a single wall dimension. A useful RFQ shows which walls are functional, what features sit nearby, and which surfaces deserve focused review.
Define what the wall does
Begin with the functional reason for the wall. Does it clear an adjacent assembly, form part of an enclosure, guide a component, or simply reduce material where no interface exists? This distinction helps a manufacturing review focus on the geometry that affects the finished part rather than treating every thin-looking area as equally critical.
If a wall forms a mating interface, provide the relevant mating-part context. Our guide to assembly fit and mating-part information explains what to share when a feature’s purpose cannot be understood from an isolated model.
Review the wall with nearby geometry
| Nearby feature | Why it matters in the RFQ | Useful drawing information |
|---|---|---|
| Deep pocket | The wall and pocket are one machining situation, not separate features. | Opening dimensions, depth, corner radii and critical floor or wall surfaces. |
| Thread or cross-hole | The feature may affect the remaining wall and functional interface. | Thread designation, depth, hole location and side of entry. |
| Mounting face | The wall may need to remain related to a seating or locating surface. | Functional reference, key dimensions and any inspection priority. |
| Cosmetic exterior | Surface expectation may differ from an internal clearance wall. | Finish callout and surfaces that matter to appearance or contact. |
A section view often communicates this more clearly than a shaded CAD screenshot. It can show the complete wall, pocket floor, adjacent feature and the direction from which the geometry must be approached.
Do not turn every wall into a critical feature
Requirements are most effective when tied to part function. Identify the walls that control fit, sealing, clearance or structural interfaces, and avoid assigning an unqualified critical requirement to all similar surfaces. Our CNC tolerance guide explains why tolerances should be connected to the dimensions that genuinely affect fit or performance.
Material and finish belong in the same package
Wall behavior is not defined by geometry alone. The controlled drawing should name the required material and any finish requirement relevant to the part. Do not rely on a color rendering, an older quotation or an email-only note to communicate a production requirement. See our guide to specifying material on a CNC RFQ for the details that make this information reviewable.
Set a practical inspection priority
If a thin wall is a functional interface, state what needs verification and from which drawing reference it should be understood. If it is only clearance, make that clear as well. Inspection requirements work best when they point to a purpose, not simply to a feature that looks delicate in CAD.
Make the review specific
ExactMach coordinates drawing-defined CNC milling, CNC turning, prototypes and custom parts around Shenzhen and Dongguan for international orders. Clear thin-wall notes give the review team the context needed to discuss the drawing-defined requirement before production is released.