The short answer
On manifold, valve-block, and housing RFQs, **cross-drilled intersection breakout** is not the same note as a [blind versus through hole](https://3dwk.com/resources/blind-vs-through-holes-cnc-rfq-notes), a [deep-hole](https://3dwk.com/resources/deep-hole-drilling-gun-drilling-cnc) depth, or a general “deburr all holes” cloud. A cross-drill is two (or more) holes that meet inside the part—oil or coolant galleries, a vent into a pocket, a port into a bore. The risk is the burr or ragged breakout where the tools meet, plus any incomplete breakthrough when one drill point stops short. Silence on which holes must fully intersect, on the allowed edge break at the junction, and on how that junction will be deburred, is what widens many [quote-new.php](https://3dwk.com/quote-new.php) **rates.v1.1** estimate bands—not the extra drill minutes alone.
This guide is for buyers packaging aluminum or similar RFQs where CAD shows two holes meeting inside a block with no intersection or deburr note. Illustrations use an **Example part** only—not a customer manifold. Sibling notes live in [vent, drain and weep holes](https://3dwk.com/resources/vent-drain-weep-holes-cnc-housings) and [edge-break chamfer and deburr callouts](https://3dwk.com/resources/edge-break-chamfer-deburr-callouts-cnc); here we focus on **intersection-breakout packaging** so estimators do not have to guess whether a 0.5 mm leftover wall is a missed breakthrough or a designed land.
What a cross-drilled intersection means for quoting
A **cross-drilled intersection** is the internal meeting of two hole axes. It is not automatically a sealing diameter, and a general “break all sharp edges” in the title block does not tell the shop how far a burr may enter a gallery or a seating bore. Process pages for automation 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](https://3dwk.com/en/cnc-3axis/al-6061.html)) assume intersection, breakout, and plug notes when lots mix functional galleries with cosmetic cover taps.
Do not bury “drill until it meets, deburr as needed” inside a notes cloud. Put **Ø6 GALLERY A MUST BREAK INTO Ø8 PORT B; FULL INTERSECTION; EDGE BREAK 0.2–0.5 AT JUNCTION; NO BURR INTO SEAT C** 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), [reaming vs boring for hole size](https://3dwk.com/resources/reaming-vs-boring-cnc-hole-size).
Breakthrough, drill point, and leftover walls
A drill point that is supposed to break into a cross hole can leave a cusp if depth is called to a sharp tip versus a full diameter. Say **full intersection** (the full diameter opens into the other hole) when flow or cleaning depends on it, and give a minimum opening if you care. If a hole is only a start or a plug location, say so—plugged start holes and functional galleries should not share one “all intersections open” note. Through versus blind still matters on the far-side breakout; see [blind vs through holes](https://3dwk.com/resources/blind-vs-through-holes-cnc-rfq-notes).
Aluminum 6061 block $/kg planning bands sit in the mid-commodity range under **rates.v1.1** material tables; material cost is rarely the intersection story—deburr access, probing, and scrap risk are.
Deburr method and seating bores
Name whether a brush, a ball-end pass, a hand tool, or a more involved pass is expected, and whether loose burrs are forbidden in a seating bore, an [O-ring groove](https://3dwk.com/resources/o-ring-groove-callouts-cnc-housings), or a thread. Do not require abrasive-flow or a named “aerospace deburr cert” unless that process is actually on the PO. If a gallery is hard to reach, say whether a witness at the junction is allowed.
Tolerance and inspection traps
Calling “no burrs anywhere” without a junction edge-break, mixing a tight bore size with an unlabeled cross-hole into that bore, or asking for 100% borescope of every unused vent, all force **needs_manual**. Default unused intersections to a simple break-through note and put a functional edge-break only on flow or seating junctions. Related: [ISO 2768 general tolerances](https://3dwk.com/resources/iso-2768-general-tolerances-cnc-rfq), [CMM sampling plans](https://3dwk.com/resources/cmm-sampling-plans-for-cnc-lots).
Illustration 1 shows an **Example part** block with a labeled full intersection and 0.2–0.5 mm edge break at a gallery-to-port junction versus a cover vent that only needs a confirmed breakthrough.
Example part walkthrough
**Example part:** Aluminum 6061-T6 block ~100×60×40 mm, Ø6 gallery A crossing Ø8 port B with a full intersection and 0.2–0.5 mm edge break, one Ø3 vent that must break into pocket C, seat C kept free of burrs, ISO 2768-m general. With STEP + **GALLERY A FULL INTERSECT PORT B, EDGE BREAK 0.2–0.5; VENT Ø3 MUST BREAK INTO POCKET C; NO BURR INTO SEAT C**, expect a usable automatic planning band on [quote-new.php](https://3dwk.com/quote-new.php). Same geometry with silent CAD and “deburr all intersections as needed” often lands DFM notes or **needs_manual**—without inventing any customer PO.
Illustration 2 contrasts a vague RFQ (“cross-drill and clean up”) versus a labeled intersection pack and the clearer estimate path.
What widens bands fastest
Unlabeled mix of functional galleries and unused vents, drill-depth to a point instead of a full opening, “no burrs anywhere” on a hard-to-reach junction, and a silent borescope of every hole. Quantity breaks help unit minutes but do not erase breakout 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 each functional **intersection** with full-versus-partial breakthrough, an edge-break range, and any bore that must stay burr-free, 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 breakout questions rather than forcing a fake price.
Common questions
Is a general “deburr all holes” enough for cross-drills?
Not when a gallery meets a seating bore or a tight port, and not as a silent default under **rates.v1.1** estimates. A title-block cloud does not say whether a small witness is allowed or whether the full diameter must open. Write the junction you care about.
Should I call depth to the drill point or to a full diameter?
If flow or cleaning needs a full opening, call a **full intersection** or a minimum opening, not only a point depth that may leave a cusp. If a small leftover web is actually a designed land, say so, so it is not treated as a missed breakthrough.
Do I need a borescope on every lot?
Only if your quality plan requires it. First-article photos or a sample borescope of functional junctions is a common middle path. “100% borescope all holes including unused vents” usually widens the band.
How is this different from a weep or vent hole?
A weep or vent is often a simple breakthrough into a pocket. A cross-drilled gallery is a designed intersection between two holes, often with a seating bore nearby. The packaging (full opening, edge break, burr-free seat) is tighter on the gallery.