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Measurement

Open STEP Surface: Area Available, Volume Unavailable

Use a known planar STEP face to distinguish measurable surface area from unavailable solid volume.

CADProps · Engineering guide · Updated 2026-10-02
Open STEP Surface: Area Available, Volume Unavailable — conceptual illustration
CADProps engineering guide · Conceptual illustration
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This is one planar face, not a closed solid. A 20 × 30 mm face has 600 mm² area. Its enclosed solid volume is unavailable; zero would misrepresent the result.

Open the matching tool and download open-surface.step.

Reproduce the check

  1. Download the unchanged public sample. It is synthetic geometry generated in the repository, not a customer model.
  2. Open it in CADProps and wait for the model canvas.
  3. Open Properties, confirm units, included components and warnings.
  4. Compare the displayed values with the analytical expectations below.
  5. Open Files → Export CSV · mm / g, then reopen the downloaded properties CSV. Keep unavailable cells separate from zero.

Expected and observed results

Property Analytical expectation Observed CSV
X (mm) 20 20
Y (mm) 30 30
A (mm²) 600 600
V (mm³) Unavailable (empty CSV cell) Unavailable (empty CSV cell)

The observed values and original CSV are recorded in the verification record. This record identifies the test environment and source revision. It describes a local verification run, not a production release.

CADProps properties for the public open-surface.step sample
CADProps local verification; the screenshot shows the actual English interface.

Download the observed CSV.

Verification scope

Sample SHA-256: 3b9cfe6e949f4ab6b11716cc6d566a908d2077acfcfa5bc08fba18e5a677029c. Generated by scripts/make_samples.py; source revision 27af64443aab95059aefa76ad27cefd267ebfbc4. Verified on 2026-10-01 with the local isolated CADProps server and Chromium; see the linked record for environment details. Numerical comparison allows 0.01 mm for extents, 0.1 mm² for area and 0.1 mm³ for volume of these simple fixtures; these are test checks, not manufacturing tolerances.

CADProps processes files on the server. Inspect source units and warnings before relying on properties. Missing components describe only loaded scope; volume requires valid closed geometry. Ordinary assembly totals sum occurrences and can double-count overlapping material; they do not compute a Boolean union. Mass requires a density you confirm. Accuracy and privacy explain the limits.

Try the check or follow the measurement workflow.

Related reading

Original article: CADProps · https://www.cadprops.com/guides/step-open-surface-volume-case/