Seal-face leaks and bore scrap often get blamed on “the other op” when both features live on the same aluminum blank—and the RFQ was split as if they were unrelated jobs.
This page covers same-part sequence: supporting face/seal milling with PCD reaming on one drawing. When milling is even in scope stays in Milling as a Supporting Process on Holemaking Lines. Here we lock datums, order, and one RFQ—not a standalone mill shopping list.
When face/seal and bore share one drawing
After M1 says milling is supporting, open this page when:
- A seal land, mounting face, or light profile must stay referenced to bore datums
- Material is a qualified non-ferrous route where custom PCD reamers still own size/finish
- Scrap mode mixes face flatness with bore size/position
Tool-role context for auto Al: Automotive Aluminum Bore Tool Map. Create→finish handoff: Carbide Drill Aluminum + PCD Reamer Process.
Sequence: face-first vs bore-first (risk talk, no fake cycle times)
| Order | Typical risk | Watch |
|---|---|---|
| Face / seal first | Clamp distortion or face stock that shifts bore entry | Datum lock; re-check create hole before ream |
| Bore finish first | Later face cut moves thin walls or datums | Leave protected stock; validate face does not steal size |
| Interleaved | Changeover convenience hides stacked scrap | One accepted-part cost sheet |
Do not publish a universal “always face first” rule or a cycle-time percent. Choose from fixture stiffness, wall thickness, and which feature fails first today.
Datum, clamp, and face flatness that steal the bore
Face flatness and clamp load can:
- Change effective reaming allowance at entry
- Walk true position so the reamer follows a bad path
- Leave a face that “passes” while the bore fails containment
Measure face and pre-hole together before you rewrite the reamer drawing. Allowance sizing stays in PCD Reamer Allowance & Pre-Hole Size—this page only flags interaction with the face op.
One RFQ for two ops vs split quotes
Put both ops on one drawing-based packet when scrap interacts:
- Mark bore GD&T and face/seal callouts on the same revision
- State sequence preference and clamp scheme
- Name create tool and finish tool intent
- Attach scrap mode (face vs bore vs both)
Split quotes make sense only when features are commercially and metrologically independent. Soft tooling path: PCD tooling · Custom cutting tools.
Cost per Good Part → RFQ
Count face rework and bore scrap against accepted parts, not against tool invoice lines alone. Combined packet → Custom Cutting Tool RFQ. Cost model language: Cost per Accepted Hole.
Frequently Asked Questions
Is this a face-mill product guide?
No. It sequences supporting milling next to PCD reaming on one part.
Should we always mill the face before reaming?
Not always—choose from fixture, wall thickness, and which scrap mode dominates.
Can we RFQ the mill alone?
Prefer one drawing packet when face and bore scrap interact; see M1 for scope boundary.
What belongs in the combined RFQ?
Drawing revision, bore + face callouts, material, sequence/clamp notes, create+finish intent, scrap mode.
Next step
Send the component drawing with face and bore callouts for a combined engineering review.