A drill map is valuable for human review, but it is not a substitute for the machine data used to manufacture the board. Check that the map and drill outputs describe the same release and hole inventory. Pay particular attention when different layer spans or plating types create several output files.
Start with the intended hole families
List through holes, nonplated holes, slots, blind or buried holes, and any other specified operations in the design. Define the properties needed to distinguish them: dimensions, shape, plating, layer span, and count. Hole diameter alone may merge operations that must remain separate.
Altium’s fabrication-drawing guidance shows drill symbols as part of a documented board drawing. That graphical representation supports review; the release still needs agreement between the legend and the actual manufacturing outputs.
Compare inventories, then locations
| Comparison | Problem it can reveal |
|---|---|
| Hole-family definitions | Different plating or spans grouped under an ambiguous symbol. |
| Counts by family | Omitted output files or a drawing from another revision. |
| Representative coordinates | Scale, origin, or mirroring differences. |
| Slot representation | A shape shown on a drawing but absent from the agreed machine-data route. |
Use the drill-tool plating audit to preserve operation identity. Then overlay outputs with the board geometry using the drill alignment check. A matching total count does not establish matching locations or manufacturing meaning.
Investigate a mismatch without editing the evidence
For example, a drill drawing may show all holes while the release archive contains only the through-hole drill file and omits a separate span. The drawing can look complete in a PDF review even though the production package is incomplete. Recreate the missing output from the correct source and regenerate the inventory comparison.
Do not manually change a legend count to match a file before identifying why they differ. Determine whether the drawing is stale, the exporter filtered a hole category, or the intended route uses another format for an operation. Record the accepted explanation with the release.
Retain the complete output list and the reconciled hole-family summary. If the supplier requests a different split or format, review the regenerated package as a new handoff, because the grouping and completeness assumptions may have changed.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist