The short answer
On metal AM RFQs, **SLM residual stress and warpage notes** are not the same thing as a [build-orientation](https://3dwk.com/resources/slm-build-orientation-notes-for-buyers) screenshot, a [support-removal](https://3dwk.com/resources/slm-support-removal-and-skim-notes) skim, or a general “stress relieve as needed” cloud. Residual stress is the locked-in thermal strain from layer-by-layer melting; warpage is the visible or measurable movement after the part leaves the plate, after supports come off, or after a first machine pass. Silence on whether a stress-relief or heat-treat step is required, on machining stock on datum faces, and on which faces may stay as-built, is what widens many [quote-new.php](https://3dwk.com/quote-new.php) **rates.v1.1** / powder estimate bands—not the hours of laser time alone.
This guide is for buyers packaging Ti-6Al-4V or similar SLM RFQs where CAD shows thin walls, tall bosses, or a machined sealing land with no stress-relief or stock note. Illustrations use an **Example part** only—not a customer aerospace bracket. Sibling notes live in [SLM build orientation](https://3dwk.com/resources/slm-build-orientation-notes-for-buyers) and [build-plate removal](https://3dwk.com/resources/build-plate-removal-notes-slm-parts); here we focus on **residual-stress and warpage packaging** so estimators do not have to guess whether a 0.5 mm facing stock is meant to clean a warped land.
What residual stress and warpage mean for quoting
SLM parts cool unevenly. Orientation, support stiffness, and section changes all affect how much a thin wall or a tall boss can move once the plate and supports are gone. Process pages for aerospace titanium ([SLM Ti-6Al-4V aerospace](https://3dwk.com/en/slm/ti-6al-4v/aerospace.html), [SLM Ti-6Al-4V](https://3dwk.com/en/slm/ti-6al-4v.html), [CNC 3-axis Ti-6Al-4V aerospace](https://3dwk.com/en/cnc-3axis/ti-6al-4v/aerospace.html)) assume stress-relief, stock, and datum notes when lots mix as-built skins with machined interfaces. This is not a CNC Ra coupon swap, and it is not a promise of a named heat-treat certificate.
Do not bury “stress relieve if needed, hold all datums” inside a notes cloud. Put **STRESS RELIEVE ON PLATE BEFORE WIRE-OFF; FACE A +0.5 STOCK, MACHINE AFTER; AS-BUILT OK ON NON-DATUM SKINS** on the PDF and mirror it in RFQ text. Background: [SLM vs CNC hybrid strategies](https://3dwk.com/resources/slm-vs-cnc-hybrid-part-strategies), [Ti-6Al-4V CNC vs SLM cost and lead time](https://3dwk.com/resources/ti6al4v-cnc-vs-slm-cost-lead-time), [what files to send for a CNC quote](https://3dwk.com/resources/what-files-to-send-for-cnc-quote).
Orientation, supports, and stock
A tall thin wall built with a shallow angle, or a boss hanging off a light [support strategy](https://3dwk.com/resources/support-strategy-notes-slm-thin-walls), is more likely to move when supports are cut. If a face must be flat or sealing, name **facing stock** and the sequence: stress relief (often while still on the plate), removal, then machining. [Downskin roughness](https://3dwk.com/resources/slm-downskin-roughness-notes-for-buyers) and [recoater clearance](https://3dwk.com/resources/recoater-clearance-notes-slm-tall-parts) still matter, but they do not replace a warpage plan. Do not ask the shop to “print it and then flatten it” without stock.
Powder and machine-time planning bands under **rates.v1.1** / powder estimates are not invoices; an extra stress-relief and a second setup usually move the band more than a small change in grams of powder.
Heat treat, HIP, and inspection
If you need a specific stress-relief or aging recipe, write the specification you actually hold and whether a certificate is required—do not invent a lab, a NADCAP stamp, or a HIP cycle the RFQ never bought. If HIP or a named heat treat is only “if needed,” expect **needs_manual**. As-built cosmetic skins and machined datums should not share one “all-over Ra and flatness” cloud.
Tolerance and inspection traps
Calling “no warpage” without a datum, stock, or sequence; inspecting a thin wall to a tight flatness in the as-built state; or mixing a 0.1 mm positional callout with zero stock on that face, all force **needs_manual**. Put functional tolerances on faces that will be machined, and give as-built faces a class that matches AM surfaces. Related: [ISO 2768 general tolerances](https://3dwk.com/resources/iso-2768-general-tolerances-cnc-rfq) for the CNC interfaces, [surface roughness Ra callouts that raise quotes](https://3dwk.com/resources/surface-roughness-ra-callouts-that-raise-quotes).
Illustration 1 shows an **Example part** SLM bracket with labeled facing stock on a datum land versus an allowed as-built thin wall after on-plate stress relief.
Example part walkthrough
**Example part:** Ti-6Al-4V SLM bracket ~80×50×40 mm, datum face A with 0.5 mm facing stock, two as-built ribs 1.5 mm thick, on-plate stress relief before wire-off, ISO 2768-m on machined interfaces. With STEP + **STRESS RELIEVE ON PLATE BEFORE WIRE-OFF; FACE A +0.5 STOCK THEN MACHINE; AS-BUILT OK ON RIBS; NO HIP UNLESS SPECIFIED**, expect a usable automatic planning band on [quote-new.php](https://3dwk.com/quote-new.php). Same geometry with silent CAD and “stress relieve as needed, hold all faces” often lands DFM notes or **needs_manual**—without inventing any customer PO.
Illustration 2 contrasts a vague RFQ (“no distortion, all faces to drawing”) versus a labeled stress-and-stock pack and the clearer estimate path.
What widens bands fastest
Unlabeled “stress relieve as needed,” zero stock on a tight datum, supports and orientation left to the shop with a no-warpage clause, and a silent HIP or certificate request. Quantity breaks help unit cost but do not erase sequence ambiguity—see [how quantity breaks change CNC unit cost](https://3dwk.com/resources/how-quantity-breaks-change-cnc-unit-cost) and [what needs_manual means](https://3dwk.com/resources/what-needs-manual-means-preliminary-quote).
What to do next
Mark **stress-relief sequence, facing stock, and as-built versus machined faces**, then upload on [quote-new.php](https://3dwk.com/quote-new.php). Service pages: [3D printing](https://3dwk.com/3d-printing-service.php), [materials](https://3dwk.com/materials.php). Treat **rates.v1.1** / powder min/mid/max as estimates, not invoices. If the UI shows **needs_manual**, answer the heat-treat and stock questions rather than forcing a fake price.
Common questions
Does every Ti-6Al-4V SLM part need stress relief?
Not as a silent default you can leave unwritten under **rates.v1.1** / powder estimates. Many structural or tightly toleranced titanium builds are stress-relieved, often while still on the plate, but a small coupon with only as-built faces may not need the same recipe. Write the sequence you actually want.
Can I skip facing stock if I add a tight flatness?
Usually no. A tight flatness on an as-built AM face is a common **needs_manual** trigger. If the face must sit or seal, give stock and machine it after stress relief and removal.
Should I request HIP on the same line as stress relief?
Only if your specification actually requires HIP. HIP is a separate, slower, and costlier step than a standard stress-relief cycle. “HIP if needed” without a spec usually widens the band.
How is warpage different from downskin roughness?
Downskin roughness is a surface class tied to orientation; warpage is movement of the geometry after cooling, removal, or machining. You can have a smooth machined land that is still out of flat if stock and sequence were never planned.