DFM for CNC Machining: Design Rules That Cut Cost

Design for Manufacturability - DFM - is the difference between a part that machines cheaply and one that fights the machine at every step.

The Rules That Matter Most

• Relax non-critical tolerances - a ±0.001 in tolerance where ±0.005 in works doubles or triples cost
• Open up corner radii - internal corners need a radius matching the tool
• Avoid deep pockets - deep, narrow pockets need long tools that deflect and slow down
• Keep walls reasonably thick - thin walls chatter and distort
• Minimize setups - features that require re-clamping add handling time

Why DFM Review Pays

Machine time is the single biggest cost driver in CNC machining. A DFM review that relaxes a non-critical tolerance or opens a corner radius can cut machine hours - and cost - by a large margin.

For the full design rule set, read DFM for CNC Machining: The Design Guide.

IsoCNC provides DFM feedback on every quote, flagging the design changes that lower cost.