CNC Machining Processes Compared
Most parts are not “CNC machined” in the abstract — they are milled, turned, ground or cut by EDM, and the process choice changes the price more than the material does. This section compares the processes we actually run, states where each one wins, and is honest about the cases where a cheaper process cannot hold the drawing.
How to read this section.
Process selection follows from geometry, tolerance and material: prismatic features point to milling, rotational features to turning, small high-precision parts to Swiss-type, and anything hardened or too tight for a cutter to grinding or EDM. Material behaviour is covered separately in Materials, and the dimensional limits in Tolerances.
Primary Processes
- CNC Milling3/4/5-axis decision table, 3+2 versus simultaneous 5-axis, machining centre types, tooling and the real cost drivers
- CNC TurningTurning versus milling decision table, lathe types compared, Swiss-type versus conventional, and live tooling options
- Swiss-Type CNC TurningWhen Swiss beats a conventional lathe, guide bushing operation, and the design rules that decide whether a part is Swiss-able
When Milling Cannot Do It
Process and material are decided together.
A part that is trivial in aluminum can be genuinely difficult in titanium or a superalloy, and the process that is cheapest on paper may not be the one that holds tolerance consistently. For the underlying depth, jump to Materials, Tolerances, or Applications.