What does DIMDEC actually control?
Autodesk's cited documentation describes DIMDEC as controlling the number of displayed decimal places for primary dimension units. The page carries a 2013 documentation date even though it is surfaced through the 2026 Help viewer. Verify the behavior and dimension style in the actual application version.
DWG Conversion is independent and is not affiliated with Autodesk. This review addresses a representation discrepancy in electrical drawing migration, not an instruction to alter approved dimensions.
Sources: Autodesk: DIMDEC documentation, dated 10 April 2013, surfaced in AutoCAD 2026 Help
Which comparisons should be kept separate?
Record the geometry measurement in the agreed drawing unit before comparing displayed labels. Inspect dimension style, text overrides and referenced endpoints independently. Displaying more decimals can reveal a difference; it does not establish which geometry is correct.
| Field | Record | Failure to avoid |
|---|---|---|
| Geometry | Measured endpoints and length in agreed units | Treat a rounded label as the measurement |
| Display precision | Dimension style and displayed decimal count | Assume more decimals mean higher source accuracy |
| Round-off | Applicable round-off setting | Confuse rounding interval with unit scale |
| Text override | Actual dimension text and override state | Copy a label that no longer represents geometry |
| Source basis | Controlled drawing and approved dimension | Choose one measurement without authority |
| Disposition | Drawing owner's decision and revised evidence | Silently stretch geometry to match a label |
How can equal labels conceal different lengths?
Illustrative example. Two fictional lines have lengths 100.04 and 100.03 in the same agreed unit. At one decimal place, ordinary decimal rounding displays both as 100.0. The labels match, but their lengths differ by 0.01.
These invented values do not set a tolerance. The reviewer records both actual measurements, their endpoint references and the display setting, then checks the approved acceptance basis. Adding decimals to the label does not prove the source PDF or rebuilt geometry is accurate to those decimals.
How should the discrepancy be closed?
Preserve the original geometry and issued source while obtaining the drawing owner's decision. A copied text label, a manual override and a dimension tied to geometry need different review evidence. Do not remove an intentional approved override without understanding its purpose.
After an authorized change, compare native geometry and issued PDF again using the agreed units and actual tolerance basis. Scaling errors remain a separate issue; a display setting cannot repair them. Engineering sign-off is performed only by the registered engineer on the job.
Common questions
What else should the bid team know?
Do identical rounded labels prove equal geometry?
No. Compare the underlying lengths and endpoints.
Does displaying more decimals establish accuracy?
No. Accuracy comes from the controlled source and approved verification basis.
Should geometry be stretched to fit copied text?
Only an authorized drawing decision can approve a geometry change.