xiehe model

Whether you wish to proofing, or are ready for mass production, reducing manufacturing costs is often a top priority when it comes to CNC turning, and there are many ways to improve your design drawings to make them faster, easier, and cheaper while maintaining quality. Here are some suggestions for you to consider about CNC turning parts.

1. Specify tolerances only when necessary

Defining strict tolerances increases costs because it both increases machining time and requires manual inspection. Tolerances should be defined carefully and only when necessary.

If a specific tolerance is not defined on the technical drawing, the part will be machised using standard tolerances (± 0.125 mm or better), which is sufficient for most non-critical features.

Internal features are particularly difficult to achieve strict tolerances. For example, when machining intersecting holes or cavities, small defects (called burrs) may appear at the edges due to deformation of the material. Parts with these characteristics need to be inspected and deburred, both manual (and time inefficient) processes that increase costs.

2. Consider the workability of the material

Workability is the ease with which a material can be cut. The higher the machinability, the faster the CNC can turn the material, reducing the cost.

The machinability of each material depends on its physical characteristics. In general, the softer (more malleable) the metal alloy, the easier it is to work.

Brass C360 is the highest machinable metal for high speed machining. Aluminum alloys such as Al 6061 can also be easily machined.

The machinability of stainless steel is 10 times lower than that of aluminum, and the processing time is at least 2 times longer. Please note that different steels have different machinability. For example, stainless steel 304 (the most common stainless steel alloy) has a machining index of 45%, while stainless steel 303 (an alloy with a very similar chemical composition) has an index of 78%, making it easier to work with.

3. Avoid (multiple) finishes

Surface treatment improves the appearance and resistance of CNC turning parts to harsh conditions, but it also increases their cost. Requiring multiple different finishes on the same part can further increase the price, since additional steps are required (for example, covering the surface).