The short answer
**Ti-6Al-4V (Grade 5)** parts can be CNC-machined from wrought bar/plate or built by **SLM** then finish-machined on datums. Cost and lead time diverge on geometry reach, stock versus powder economics, and whether the line stays in automatic **rates.v1.1** bands or flips to **needs_manual**. Put process intent on the RFQ before comparing screenshots on [quote-new.php](https://3dwk.com/quote-new.php).
This guide is for buyers trading CNC vs SLM on titanium. Illustrations use an **Example part** only. It is distinct from general machining notes in [titanium Ti-6Al-4V for machined parts](https://3dwk.com/resources/titanium-ti6al4v-for-machined-parts) and from Inconel process forks in [IN625 vs IN718 CNC vs SLM](https://3dwk.com/resources/in625-vs-in718-cnc-vs-slm-buyers).
When CNC from wrought is the default
Prismatic brackets, lugs, and pockets that cutters can reach usually belong on CNC. Wrought Ti-6Al-4V has known heat chemistry and machinability narratives shops already price. Expect slower feeds than aluminum—titanium is not “6061 with a higher mid.” Related: [CNC cost drivers](https://3dwk.com/resources/cnc-machining-cost-drivers-buyer-guide), [CNC lead time](https://3dwk.com/resources/cnc-machining-lead-time-buyer-guide), [DFM checklist before an online CNC quote](https://3dwk.com/resources/dfm-checklist-before-online-cnc-quote).
**rates.v1.1** planning (estimates, not invoices): hot-alloy / high-$ lines often auto-route to **needs_manual** above configured thresholds—same pattern as IN718/IN625 (bar ~$55–60/kg, CNC time coeff ×2.5) and CoCr (coeff ×2.2, SLM powder ~$150/kg; 17-4PH powder ~$70/kg for comparison). Treat titanium lines with the same honesty: do not paste an aluminum mid onto a Ti RFQ. Soft plastics (PA66 bar ~$5/kg, coeff ×0.8) are a different universe—never reuse those mids.
When SLM + finish machine makes sense
Internal channels, lattice-like lightening, or envelopes that would force many setups or EDM on wrought stock are SLM candidates. Plan for as-built surfaces on non-mates and CNC on sealing faces, bores, and datums. Powder economics and build orientation drive calendar time differently than spindle hours. Parallel RFQs (CNC path vs SLM path) beat a single ambiguous “titanium, either process” note. See [CNC vs 3D printing when to choose](https://3dwk.com/resources/cnc-vs-3d-printing-when-to-choose) and [cobalt chrome SLM vs CNC](https://3dwk.com/resources/cobalt-chrome-slm-vs-cnc-cost-lead-time) for analogous forks. Wire EDM as a third path appears only when cutters cannot reach and additive is out of scope—see [wire EDM for precision parts](https://3dwk.com/resources/wire-edm-for-precision-parts).
Illustration 1 shows an **Example part** process fork: prismatic lug → CNC; internal channels → SLM + machined pads.
Cost drivers that move the band
- Stock form and buy-to-fly on CNC (thick plate remnant waste)
- Spindle time and tool wear (Ti is sticky; aggressive callouts inflate time)
- SLM build hours, support removal, stress relief, HIP if required
- Finish-machine allowance on datum pads
- Inspection density (CMM on every thin wall vs mates only)
Call heat-treat / stress-relief intent. Ambiguous “aerospace titanium” without process path is a classic **needs_manual** trigger—see [what needs_manual means](https://3dwk.com/resources/what-needs-manual-means-preliminary-quote). 17-4PH heat-treat lot adders (~+$60/lot H900/H1025 under **rates.v1.1** estimates) are a reminder that post-process blocks matter on any alloy—label Ti stress-relief the same way.
Lead time is not the inverse of unit cost
A CNC Ti blank may ship faster for simple geometry while SLM wins calendar on complex internals once the build queue clears. State need-by separately from process preference. Qty ladders still matter—prototype 1–2 vs bridge 10 change both powder amortization and bar drops. Background: [how quantity breaks change CNC unit cost](https://3dwk.com/resources/how-quantity-breaks-change-cnc-unit-cost), [reading a preliminary quote](https://3dwk.com/resources/reading-preliminary-online-quote-min-mid-max).
Illustration 2 contrasts a thin “Ti-6Al-4V, machine complete” note versus a process-path RFQ block and clearer estimate routing.
Packaging the RFQ
- Alloy + condition (annealed / STA if you care)
- Preferred path: CNC wrought **or** SLM + finish machine
- Datums and post-process skims
- Finish list (anodize rare on Ti; coatings only if functional)
- Qty and need-by
- Files: STEP + PDF—see [what files to send](https://3dwk.com/resources/what-files-to-send-for-cnc-quote)
Incomplete packs still upload; they produce wider bands or manual review. Do not invent mill certs or customer logos in the upload notes.
Tolerance and surface realism
Do not put Ra 0.4 on every as-built SLM wall. Put fine finishes on CNC datum faces. Blanket ±0.01 on organic SLM envelopes invites clarification. Related: [surface roughness Ra](https://3dwk.com/resources/surface-roughness-ra-for-machined-parts), [GD&T basics](https://3dwk.com/resources/gdt-basics-for-buyers).
Example part walkthrough
**Example part:** Ti-6Al-4V clevis lug, ~70×40×25 mm, two Ø8 bores, ISO 2768-m, sealing faces Ra 1.6. Prismatic version → CNC wrought planning path. Same outer envelope with internal coolant-style channels → SLM + machine bores/faces on a parallel line. Upload both intents on [quote-new.php](https://3dwk.com/quote-new.php) rather than one vague mid—without inventing customer aerospace invoices.
What to do next
Pick the process family that matches geometry, label it on the PDF, then request an estimate on [quote-new.php](https://3dwk.com/quote-new.php). Service pages: [CNC machining](https://3dwk.com/cnc-machining-service.php), [metal 3D printing](https://3dwk.com/metal-3d-printing-service.php), [materials](https://3dwk.com/materials.php). **rates.v1.1** figures are estimates.
Common questions
Is Ti-6Al-4V always more expensive than 17-4PH?
Often on spindle time and stock, but geometry and qty dominate. Compare like-for-like RFQs; do not swap alloys mid-screenshot.
Do I need HIP on every SLM Ti part?
Only if your requirement set says so. Calling HIP “just in case” changes lead time and cost narrative—state it explicitly.
Can I reuse an Inconel SLM mid for titanium?
No. Re-parse with the correct alloy and path. Neighbor-line mids are not invoices.
Does STA condition change CNC vs SLM choice?
Condition mainly changes machinability and strength narrative after the process family is chosen. Still label path first, then condition.