The short answer
On a CNC housing RFQ, an **O-ring groove** is not a generic “slot for seal.” Gland **width**, **depth**, **corner radius**, and **surface finish** drive crush, leak risk, and toolpath family. Silence on those callouts is what widens many [quote-new.php](https://3dwk.com/quote-new.php) **rates.v1.1** estimate bands—not the housing envelope alone.
This guide is for buyers packaging aluminum or stainless housings with static or face seals. Illustrations use an **Example part** only—not a customer manifold. Related notes live in [O-ring groove design CNC housings](https://3dwk.com/resources/o-ring-groove-design-cnc-housings) and [blind vs through holes CNC RFQ notes](https://3dwk.com/resources/blind-vs-through-holes-cnc-rfq-notes); here we focus on **groove callouts that estimators can price** without guessing crush or finish.
What groove callouts mean for quoting
A face gland needs width × depth (and often a corner R max), plus a finish note on the sealing land. A piston/bore gland adds diameter stack and lead-in. Process pages for automation and robotics aluminum ([CNC 3-axis Al 6061 automation](https://3dwk.com/en/cnc-3axis/al-6061/automation.html), [CNC 5-axis Al 6061 automation](https://3dwk.com/en/cnc-5axis/al-6061/automation.html), [CNC 3-axis Al 6061 robotics](https://3dwk.com/en/cnc-3axis/al-6061/robotics.html)) assume gland notes when lots mix sealing faces and cosmetic exteriors.
Do not bury “O-ring groove per catalog” inside a notes cloud. Put **GLAND W×D**, dash size or ISO gland reference, **Ra on seal land**, and **NO BREAK on land** on the PDF and mirror it in RFQ text. Background: [DFM checklist before an online CNC quote](https://3dwk.com/resources/dfm-checklist-before-online-cnc-quote), [what files to send for a CNC quote](https://3dwk.com/resources/what-files-to-send-for-cnc-quote).
Width, depth, corner R and tool access
Gland width and depth must match the O-ring dash and squeeze target; silent “make it seal” forces DFM loops. Internal corner R smaller than the planned cutter widens bands. Soft stock (PA66 time coeff ×0.8) is uncommon for pressure housings; aluminum and stainless dominate. Harder alloys (17-4PH ×1.4, IN718/IN625 ×2.5) amplify groove-tool wear; aggressive deep narrow glands with tiny R frequently auto-route toward **needs_manual** when mid-line bands exceed planning thresholds under **rates.v1.1** estimates.
If Type II anodize or chem film follows, say whether the gland is masked, machined after finish, or allowed to coat—see [as-machined before Type II anodize](https://3dwk.com/resources/as-machined-before-type-ii-anodize), [chem film vs Type II anodize](https://3dwk.com/resources/chem-film-vs-type-ii-anodize-aluminum).
Bar $/kg planning bands (estimates only): PA66 ~5, 17-4PH ~9, IN718 ~55. Material cost is rarely the gland story—geometry stack and finish keep-outs are.
Finish, flash and clamp keep-outs
Sealing lands hate serrated vise marks and uncontrolled chamfers. Soft jaws or pads help—see [soft jaws vs vise CNC production lots](https://3dwk.com/resources/soft-jaws-vs-vise-cnc-production-lots). Name clamp keep-outs and **NO BREAK** on the land. Related edge notes: [chamfer vs fillet edge break](https://3dwk.com/resources/chamfer-vs-fillet-edge-break-cnc-rfq) once published, and [edge break chamfer deburr callouts](https://3dwk.com/resources/edge-break-chamfer-deburr-callouts-cnc).
Tolerance and inspection traps
Calling only “O-ring groove” without W×D, or putting ±0.01 on every gland wall without a functional reason, fights automatic bands. Default non-critical envelope to ISO 2768-m; put functional tolerances on crush-critical walls and land flatness. Related: [GD&T callouts that raise CNC quote bands](https://3dwk.com/resources/gdandt-callouts-that-raise-cnc-quote-bands), [surface roughness Ra for machined parts](https://3dwk.com/resources/surface-roughness-ra-for-machined-parts), [CMM sampling plans for CNC lots](https://3dwk.com/resources/cmm-sampling-plans-for-cnc-lots).
Illustration 1 shows an **Example part** face gland with labeled width, depth, corner R max, and seal-land Ra.
Example part walkthrough
**Example part:** 6061-T6 housing ~100×80×40 mm, one face O-ring gland for a static cover, ISO 2768-m general, land Ra 1.6. With STEP + **GLAND 2.70×1.42 (AS568-2xx class); LAND Ra 1.6; NO BREAK ON LAND; TYPE II AFTER MACHINE — MASK GLAND**, expect a usable automatic planning band on [quote-new.php](https://3dwk.com/quote-new.php). Same geometry with silent CAD and “O-ring groove / seal somehow” often lands DFM notes or **needs_manual**—without inventing any customer PO.
Illustration 2 contrasts a vague RFQ (“add O-ring groove”) versus a labeled W×D / Ra / mask block and the clearer estimate path.
What widens bands fastest
Unlabeled gland size, finish silent on the land, anodize over unmasked glands, and 100% air-decay of every prototype without a stated criterion. Quantity breaks help unit minutes but do not erase seal risk—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 **W×D**, dash or standard reference, **Ra on land**, mask/finish intent, then upload on [quote-new.php](https://3dwk.com/quote-new.php). Service pages: [CNC machining](https://3dwk.com/cnc-machining-service.php), [materials](https://3dwk.com/materials.php). Treat **rates.v1.1** min/mid/max as estimates, not invoices. If the UI shows **needs_manual**, answer the gland questions rather than forcing a fake firm price.
Common questions
Can I point to a catalog dash only?
Dash size helps, but still name gland W×D or the ISO/AS gland table you follow so toolpaths match crush intent under **rates.v1.1** estimates.
Do I need Ra 0.4 on every gland?
Usually no. Many static face seals work at Ra 1.6–3.2. Tighter Ra raises polish or fine-finish minutes—see [surface roughness Ra for machined parts](https://3dwk.com/resources/surface-roughness-ra-for-machined-parts).
How does anodize interact with glands?
Coating thickness changes crush. Mask, machine after coat, or design for coated thickness—state which.
Should bore glands follow the same labeling habit?
Yes. Add diameter stack and lead-in notes; the W×D / Ra / no-break discipline still applies.