Design Guidelines for CNC Machining

In the competitive world of custom part manufacturing, understanding Design for Manufacturability (DFM) is crucial for success. For businesses seeking reliable, highquality CNC machined components, adhering to established design guidelines is the most effective way to ensure project efficiency, costeffectiveness, and superior results. As a professional onestopshop for CNC machining services, we have compiled key design principles to help you optimize your parts for production.


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Internal Sharp Corners and End Mills
CNC cutting tools, primarily end mills, are cylindrical and cannot produce perfectly sharp internal corners. Always design internal vertical corners with a radius. A good rule of thumb is to use a corner radius slightly larger than the intended tool radius to allow for tool path overlap and ensure a clean cut. Undercuts are possible but require specialized tools and should be communicated early in the design phase.

Cavity and Pocket Depths
Deep cavities with small tooling can lead to tool deflection, vibration, and breakage, resulting in poor surface finish and dimensional inaccuracies. We recommend limiting cavity depths to 34 times the tool diameter. For deeper pockets, consider designing with a variable depth or using larger tools in the initial roughing operations.

Wall Thickness

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Thin walls are prone to vibration during machining, which can cause poor surface finish or even failure. Maintaining a minimum wall thickness is essential. For metals, we recommend a minimum of 0.8 mm, and for plastics, 1.5 mm. Increasing wall thickness significantly enhances the part's rigidity and machinability.

Threads and Holes
Standardize your thread sizes wherever possible. While we can produce custom threads, using standard sizes (e.g., UNC, UNF, Metric) reduces cost and lead time. For blind holes, remember to design a depth that exceeds the threaded portion to provide space for unused threads and cutting chips.



Text and Lettering
Embossed text is preferable to engraved text as it requires less material removal and machining time. If engraving is necessary, use a simple, sansserif font and ensure the character size and depth are sufficient for clarity and durability.

Material Selection
The choice of material directly impacts the part's functionality, cost, and lead time. We offer a wide range of metals and plastics. Consider factors like mechanical properties, weight, corrosion resistance, and machinability. Our engineering team is always available to provide material recommendations tailored to your application.

By integrating these fundamental guidelines into your design process, you can dramatically streamline the transition from prototype to production. This collaboration between design and manufacturing minimizes revisions, accelerates delivery, and reduces overall costs. Partner with us to leverage our expertise and transform your optimized designs into precisionmachined reality, driving growth for your products in the global market.