The short answer
Many CNC parts need **milled faces and turned diameters on the same component**. How you define datums, stock, and setup order changes both manufacturability and the [quote-new.php](https://3dwk.com/quote-new.php) path. Package mill+turn intent clearly so **rates.v1.1** estimate bands stay honest instead of defaulting to **needs_manual**.
This guide is for buyers RFQing hybrid prismatic/rotational parts. Illustrations use an **Example part** only—not a customer routing sheet.
Why mill+turn is a quote category, not a buzzword
A flange with a precision OD, a housing with a turned register, or a shaft with milled flats all cross process families. Shops may use live-tool turning, mill-turn centers, or separate lathe then mill setups. Automatic parsers need enough notes to know which story you mean. Related: [Swiss turning vs CNC lathe](https://3dwk.com/resources/swiss-turning-vs-cnc-lathe-small-parts), [turned stainless shaft drawing guide](https://3dwk.com/resources/turned-stainless-shaft-drawing-guide), [3-axis vs 5-axis for buyers](https://3dwk.com/resources/3-axis-vs-5-axis-cnc-for-buyers), [CNC cost drivers](https://3dwk.com/resources/cnc-machining-cost-drivers-buyer-guide).
Datum strategy that survives both processes
Pick a primary datum that both turning and milling can respect—often a turned diameter or face. Do not stack conflicting A-datums (“face A from mill” vs “shoulder A from lathe”) without a note. Call which features are finished after the other process if stock is left. See [GD&T basics for buyers](https://3dwk.com/resources/gdt-basics-for-buyers) and [flatness / parallelism / perpendicularity](https://3dwk.com/resources/flatness-parallelism-perpendicularity-machined-parts).
Illustration 1 shows an **Example part** mill+turn feature map: turned OD/shoulder versus milled flats/pockets.
Setup count and machine class assumptions
- Live-tool lathe: radial holes and light milling in one chucking—great when features allow
- Separate turn then mill: common for larger flanges; state if concentricity must survive re-chuck
- Mill-turn / multitasking: powerful but easy to over-specify in notes
If positional indexing on a mill is enough for hex flats, say so. “Must be 5-axis mill-turn” language raises class without buying concentricity you already get from a lathe.
Tolerances: what to tighten on hybrid parts
Tighten turned bearing journals and sealing ODs; tighten milled bolt patterns and sealing flats. Do not blanket ±0.01 mm across every turned and milled edge. Surface roughness: journals may need Ra 0.8 while milled pockets stay Ra 3.2—see [surface roughness Ra](https://3dwk.com/resources/surface-roughness-ra-for-machined-parts). Threads: specify rolled vs cut if it matters; depth still required—[designing threads](https://3dwk.com/resources/designing-threads-and-tapped-holes).
Material and rates.v1.1 context
State alloy and condition. **rates.v1.1** planning bands (estimates): bar $/kg PA66 ~5, 17-4PH ~9, IN718 ~55, IN625 ~60; CNC machine-time coefficients PA66 ×0.8, 17-4PH ×1.4, IN718/IN625 ×2.5, CoCr ×2.2. Hybrid setups multiply handling; hot-alloy lines above configured USD thresholds auto-route to **needs_manual**. 17-4PH H900/H1025 lot heat treat often ~+$60/lot when selected—call sequence relative to turn/mill finishes.
Knurls, grooves and secondary features
Knurls on turned shafts plus milled keyways need clear callouts so shops do not assume decorative texture everywhere. Related: [knurling on CNC turned shafts](https://3dwk.com/resources/knurling-on-cnc-turned-shafts), [O-ring groove design](https://3dwk.com/resources/o-ring-groove-design-cnc-housings), [counterbore / countersink / spotface](https://3dwk.com/resources/counterbore-countersink-spotface-cnc-bolted-joints).
Illustration 2 contrasts a vague “machine complete” note versus a process-ordered RFQ block and the resulting estimate clarity.
Packaging the RFQ
- STEP + PDF with mill vs turn feature notes
- Datum scheme that survives both
- Concentricity / runout only where functional
- Qty and whether prototype allows separate setups
- Finish after which process (passivate, anodize on aluminum hybrids, etc.)
Upload on [quote-new.php](https://3dwk.com/quote-new.php). Services: [CNC machining](https://3dwk.com/cnc-machining-service.php), [materials](https://3dwk.com/materials.php). Reading bands: [preliminary quote min/mid/max](https://3dwk.com/resources/reading-preliminary-online-quote-min-mid-max).
Example part walkthrough
**Example part:** 6061-T6 flange shaft, Ø40 turned register, 8 mm plate flange milled to 80×80 with four M5, ISO 2768-m, runout 0.05 on register to flange face, clear Type II optional on cosmetics. Expect an automatic planning band when notes say turn register then mill flange pattern. Same envelope marked “±0.01 all over, 5-axis only, anodize then cut threads TBD” often goes wide or manual—without inventing a customer traveler.
What to do next
Decide lathe-primary vs mill-primary, lock datums, then request a range on [quote-new.php](https://3dwk.com/quote-new.php). Treat **rates.v1.1** outputs as estimates. If needs_manual appears, clarify setup intent rather than pasting a neighbor prismatic mid onto a hybrid line.
Stock selection for hybrid envelopes
Bar stock favors turned-primary parts; plate favors milled flanges with a secondary turned boss if you weld or assemble—but welded stories are out of scope for a single CNC line. For one-piece hybrids, choose the stock that wastes less and still leaves chucking material. Remnants and minimum bar lengths quietly move unit cost at low qty—tie this to your quantity ladder when relevant ([how quantity breaks change CNC unit cost](https://3dwk.com/resources/how-quantity-breaks-change-cnc-unit-cost) once published alongside this guide).
Deburr and edge break across processes
Turned sharp corners and milled pocket edges both need edge intent. A global “break all edges 0.1–0.3” is fine for prototypes; sealing edges and bearing chamfers deserve explicit callouts so shops do not tumble features you need sharp. See [edge break / chamfer / deburr](https://3dwk.com/resources/edge-break-chamfer-deburr-callouts-cnc) and [bead blast vs tumble vs vibratory](https://3dwk.com/resources/bead-blast-vs-tumble-vs-vibratory-finish).
Files that help mill+turn quotes
Prefer STEP solids plus a PDF that marks which diameters are turned and which faces are milled. PMI-only packs without a human-readable process note still confuse floor communication. Related: [what files to send for CNC quote](https://3dwk.com/resources/what-files-to-send-for-cnc-quote), [DFM checklist](https://3dwk.com/resources/dfm-checklist-before-online-cnc-quote).
Common questions
Is Swiss turning required for small mill+turn parts?
Only when diameter, length, and volume fit Swiss economics. Many prototypes are happier on conventional CNC lathe + mill. See the Swiss vs lathe guide linked above.
Can I model everything as a mill and hope?
You can, but concentric turned journals modeled as milled approximations confuse stock and tolerance stories. Model true cylinders for turned features.
Does mill+turn always cost more than pure mill?
Often yes in handling; sometimes a turned OD is cheaper than milling a large cylindrical boss from plate. Geometry decides—ask for parallel options when unsure.