The short answer
For metal AM RFQs, **build orientation** is a quote input—not an afterthought. Orientation drives support volume, down-skin roughness, heat accumulation, and which faces need CNC skim. Silence on preferred Z and keep-out faces widens [quote-new.php](https://3dwk.com/quote-new.php) powder and post-machine **rates.v1.1** estimate bands.
This guide is for buyers packaging SLM / LPBF RFQs. Illustrations use an **Example part** only—not a customer flight article. Related: [minimum wall CNC vs SLM for buyers](https://3dwk.com/resources/minimum-wall-cnc-vs-slm-for-buyers), [CNC vs 3D printing when to choose](https://3dwk.com/resources/cnc-vs-3d-printing-when-to-choose), [Ti6Al4V CNC vs SLM cost and lead time](https://3dwk.com/resources/ti6al4v-cnc-vs-slm-cost-lead-time).
What orientation notes belong on an RFQ
State preferred build axis, faces that must stay support-free if possible, and faces that will be CNC skimmed anyway. Powder pages for aerospace and medical stacks ([SLM Ti-6Al-4V aerospace](https://3dwk.com/en/slm/ti-6al-4v/aerospace.html), [SLM 316L aerospace](https://3dwk.com/en/slm/316l/aerospace.html), [SLM AlSi10Mg aerospace](https://3dwk.com/en/slm/alsi10mg/aerospace.html)) still need orientation when internal channels and mating pads compete.
Put **BUILD Z** and **SUPPORT OK / KEEP-OUT** notes on the PDF. Do not only stamp “print somehow.” Background: [what files to send for a CNC quote](https://3dwk.com/resources/what-files-to-send-for-cnc-quote) (STEP + notes pattern still applies), [DFM checklist before an online CNC quote](https://3dwk.com/resources/dfm-checklist-before-online-cnc-quote).
Supports, powder removal and skim pads
Heavy supports on cosmetic or flow faces raise removal minutes and witness risk. Internal channels need powder-exit paths—orientation that traps powder creates **needs_manual** loops. Mate pads that will be CNC skimmed can often accept supports; sealing lands may not. Call skim stock explicitly (e.g. +0.5 mm on Datum A pads).
Powder $/kg planning bands (estimates only under **rates.v1.1**): 17-4PH ~70, IN718 ~120, IN625 ~130, CoCr ~150. Orientation rarely changes powder $/kg, but it changes support mass, recoater risk, and post-CNC time. CNC time coeffs on skim ops still scale (17-4PH ×1.4, IN718/IN625 ×2.5, CoCr ×2.2); PA66 ×0.8 is irrelevant to metal powder but matters if polymer prototypes share the study.
When orientation can stay flexible
If all exterior faces will be machined and channels are open, a supplier-chosen orientation with your keep-outs listed may be enough. If fatigue, grain-ish anisotropy concerns, or optical cosmetics dominate, lock Z yourself. Related medical-adjacent reading: [cobalt chrome SLM vs CNC](https://3dwk.com/resources/cobalt-chrome-slm-vs-cnc-cost-lead-time), [CoCr SLM medical-adjacent brackets DFM](https://3dwk.com/resources/cocr-slm-medical-adjacent-brackets-dfm-quotes).
Illustration 1 shows an **Example part** with Z along the thin wall versus Z along the thick pad, and where supports land.
Down-skin, angles and cosmetic callouts
Steep overhangs and down-facing skins print rougher than up-skins. If a cosmetic or sealing face cannot accept that texture, either reorient, add machine stock, or accept a secondary finish note. State maximum unsupported angle you will allow if your internal DFM has one; otherwise list faces that must not be down-skin. Hybrid RFQs that compare SLM brackets to plate CNC housings should keep orientation notes on the AM line item only—do not paste BUILD Z onto a pure CNC sibling.
When drone or medical envelopes share powder families, still verify the live combo page before linking—orientation guidance travels with the geometry, not the marketing label.
Heat, warping and hot-alloy notes
Tall thin walls in the Z direction can accumulate heat differently than flat builds. IN718/IN625/CoCr parts with aggressive overhangs and line mids above ~$2000 planning bands often need **needs_manual** review—orientation notes reduce that loop. Bar $/kg planning bands for any parallel CNC study (estimates only): PA66 ~5, 17-4PH ~9, IN718 ~55, IN625 ~60. 17-4PH heat treat H900/H1025 +$60/lot estimate language applies when you request precip hardening after build—say so separately from orientation.
Example part walkthrough
**Example part:** Ti-6Al-4V bracket ~80×40×25 mm, two Ø8 bores to be CNC skimmed, internal channel with two powder exits, preferred BUILD Z along the 25 mm height so exits face up, supports allowed on non-mate ribs only, +0.6 mm stock on bore pads. With STEP + orientation block, expect a clearer powder + skim planning band on [quote-new.php](https://3dwk.com/quote-new.php) than “print best effort.” Same CAD with silent orientation often lands DFM questions—without inventing any customer build log. Also useful: [SLM Ti-6Al-4V medical](https://3dwk.com/en/slm/ti-6al-4v/medical.html), [SLM Ti-6Al-4V drone](https://3dwk.com/en/slm/ti-6al-4v/drone.html).
Illustration 2 contrasts a vague AM note versus an orientation + support keep-out RFQ block.
What widens bands fastest
No Z preference, trapped powder channels, “no supports anywhere” on overhang-heavy CAD, and skim pads left at as-built tolerance. Quantity breaks help unit cost but do not erase support removal—see [how quantity breaks change CNC unit cost](https://3dwk.com/resources/how-quantity-breaks-change-cnc-unit-cost), [what needs_manual means](https://3dwk.com/resources/what-needs-manual-means-preliminary-quote).
What to do next
Mark BUILD Z, support keep-outs, skim stock, then upload on [quote-new.php](https://3dwk.com/quote-new.php). Service pages: [metal 3D printing](https://3dwk.com/metal-3d-printing-service.php), [CNC machining](https://3dwk.com/cnc-machining-service.php), [materials](https://3dwk.com/materials.php). Treat **rates.v1.1** / powder estimates as planning bands, not invoices.
Common questions
Must buyers always lock orientation?
Lock it when channels, cosmetics, or fatigue-critical skins care. Otherwise list keep-outs and allow engineering to propose Z.
Do supports always mean worse quotes?
Supports add removal time but can enable safer builds. Forbidden supports on hard overhangs often cost more via scrap risk or **needs_manual**.
How do powder $/kg estimates interact with orientation?
Orientation changes support mass and post-work more than list powder $/kg. Still label powder family so bands use the right **rates.v1.1** powder estimate.
Is SLM orientation the same as CNC fixture orientation?
No. Fixture notes belong on skim ops; build Z belongs on the AM step. Put both when the RFQ is hybrid.