DFM Guide · Turn-Mill

Combined operations.
One setup.
Turn-mill efficiency.

Turn-mill machines combine CNC turning with live-tool milling. Cross-holes, flats, slots, hex features added without separate setup. Specific design considerations apply.

Free DFM Review CNC turning

01 · Key principles

Key principles.

Live tooling on lathe

Cross-features

Live tools cut cross-holes, flats, slots on rotating workpiece. Single setup completes parts.

Y-axis turn-mill

Off-center features

Y-axis turn-mill enables off-center features impossible on standard lathes.

Sub-spindle

Backside machining

Sub-spindle picks up part for backside machining — both ends complete.

Bar feed automation

Continuous production

Bar-fed turn-mill runs unattended. Production volumes 200+ economical.

Tolerance preservation

Single setup

One-setup machining preserves tolerance vs separate operations.

Material flexibility

Round bar stock

Best for bar-stock material. Square/rectangle requires turning fixtures.

FAQ

When does turn-mill win vs separate operations?

Parts needing both turning (round geometry) and milling (cross-features) features. Single setup vs 2-3 separate setups dramatically reduces cost and improves tolerance.

Y-axis turn-mill capabilities?

True 3D milling on rotating parts. Off-center holes, complex 3D features. Premium over standard live-tool turn-mill.

Sub-spindle benefits?

Eliminates secondary operation for backside features. Both ends of part complete in single machine cycle.

Bar feed economics?

Bar feeders enable unattended production. Lights-out machining with 200+ bar capacity. Per-piece cost drops significantly.

Material restrictions?

Bar stock material economical. Casting blanks need fixturing. Plate/forged stock typically not turn-mill candidate.

Tolerance achievable?

Standard turn-mill ±0.025 mm. Y-axis turn-mill ±0.025 mm. Tighter for ground bores or post-machined critical features.