Turning vs. milling
Two production processes, one goal: your perfect component. We explain the differences, show when each process is the right one, and why combining them is often the best answer.
Turning produces rotationally symmetric parts (shafts, bushings), milling produces prismatic geometries (housings, plates). The choice depends on part geometry, quantity and the tolerance required. We combine both processes in a single setup.
How the difference works
The fundamental difference: in turning the workpiece rotates, in milling the tool rotates. That decides which geometries are possible.
Which shape suits which process?
Turning produces rotationally symmetric parts: shafts, bolts, bushings, flanges, anything round. The axial symmetry allows high accuracy and excellent surfaces.
Milling handles prismatic and flat geometries: housings, plates, pockets, slots. With 5-axis milling, free form surfaces and complex 3D contours become possible too.
Turning vs. milling in detail
| Criterion | CNC turning | CNC milling |
|---|---|---|
| Workpiece | Rotates (chuck) | Fixed (vice/clamp) |
| Tool | Stationary or linear | Rotates (milling spindle) |
| Typical parts | Shafts, bolts, bushings | Housings, plates, pockets |
| Tolerances | ±0.005 mm achievable | ±0.01 mm standard |
| Surface | Ra 0.4 achievable | Ra 0.8 standard |
| Hourly rate | Lower | Higher |
| Automation | Bar feeder (24/7) | Pallet changer |
When to turn, when to mill?
Choose turning when:
- ✓ The part is rotationally symmetric (shaft, bolt, bushing)
- ✓ High concentricity is required
- ✓ Series parts are made from bar stock
- ✓ Threads (internal or external) are needed
- ✓ Unattended 24/7 production with a bar feeder is possible
Choose milling when:
- ✓ The part is prismatic or flat (housing, plate)
- ✓ Pockets, slots or free form surfaces are needed
- ✓ Machining from several sides is required
- ✓ Complex 3D geometries (5-axis) are involved
- ✓ Large components (above 250 mm) have to be machined
Or both: complete machining
Modern CNC lathes with driven tools combine turning and milling in a single setup. That saves re-clamping time, eliminates positional errors and lowers the unit cost.
Fewer setups
Turning, milling and drilling in one pass. No re-clamping, no positional errors.
Shorter lead time
One operation instead of two or three. Parts are finished sooner.
Higher accuracy
No re-clamping errors, every operation references the same datum.
Frequently asked questions
In turning the workpiece rotates and the tool stays put or moves linearly. In milling the tool rotates and the workpiece is fixed. Turning suits round parts, milling suits prismatic geometries.
CNC turning generally carries lower hourly rates than CNC milling. Turned parts from the bar feeder are particularly economical in series. Milled parts often need several setups, which pushes the price up.
Yes. Modern lathes such as our DMG MORI NLX 2000 have driven tools and a Y axis. Cross holes, flats and slots can be produced directly on the turned part without re-clamping.
Turning reaches ±0.005 mm (on H7/g6 fits). In milling, ±0.01 mm is the standard. Both processes reach IT6 tolerances where required.
5-axis milling uses three linear plus two rotary axes. The workpiece can be machined from almost any angle, which suits complex 3D contours in a single setup. Our Ecomill 70 works with indexed 5-axis positioning rather than simultaneous 5-axis motion.
A bar feeder pushes bar stock into the CNC lathe automatically. That lets series run unattended around the clock, 24/7 without an operator.
Enquire about a turned or milled part
Send us your drawing. We recommend the best process and give you a fair quote within 24 hours.
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