ASSEMBLY CHECK / FROM DRY FIT TO FIXING

Check the diagonals.
Keep the evidence.

Compare two corner-to-corner readings, account for measuring uncertainty, and record the physical checks before the next fixing operation.

Check my assembly ↓Local to your browser
Diagonal A connects upper left to lower right; diagonal B connects upper right to lower left.A · upper left → lower rightB · upper right → lower leftSAME FACE · SAME CORNER REFERENCES
Diagram identifies the readings; it is not a measured deformation preview.

Your draft and snapshots stay in this browser. No account or upload is needed.

01 / ENTER A MEASURED PAIR

One face. Four corners.

The editable sample is not a saved inspection. Choose your own tolerance and uncertainty; the defaults are examples, not shop standards.

A: upper left → lower right. B: upper right → lower left. Width and height define the intended rectangle, not measured acceptance limits.

02 / Confirm the physical checks

Save open reviews too. A snapshot preserves the entered values and check state without certifying the build.

Example: borderline reading

A = 1,000 mm; B = 1,002 mm; uncertainty ±0.5 mm. The possible difference is 1–3 mm, which crosses a 2 mm limit.

03 / KEEP THE CHECK HISTORY

Saved snapshots

0 / 200 saved

No saved checks yet.

THE BENCH METHOD

A reading is one part
of the review.

Matching diagonals are useful when the opposite sides, reference corners and plane are checked too. Keep the actual fit inspection alongside the numerical comparison, then take a new reading if clamping or fixing changes the geometry.

By WoodCutTool editorial team · Updated 2026-10-09. This tool stores records locally and offers separate exports. It does not assess structural strength, joint capacity or installation requirements.

How the difference range works

Observed gap = |A − B|. With uncertainty ±u on each reading, the possible gap is max(0, gap − 2u) through gap + 2u. The whole range must fit inside your limit for a “within” reading state. If it crosses the limit, the state is borderline; if the lower bound exceeds the limit, it is outside. This is a bounded comparison, not a statistical confidence interval.

What the reference diagonal means

Reference diagonal = √(width² + height²). A 600 × 800 mm intended rectangle has a 1,000 mm diagonal. This comparison does not validate the actual side dimensions or plane. Equal diagonals alone can occur in a tapered shape; inspect sides and corners as well.

What completes a review

A review is complete only when the readings are within your chosen tolerance and all four physical checks are confirmed. Any relevant adjustment needs another check. The tool gives no universal tolerance, clamp force or correction distance; use the project requirements and physical trial fit.

How to preserve the records

Save separate snapshots before and after adjustments. CSV contains millimeter values, reading bounds, status and check states. JSON preserves the draft and records for reviewed replacement on import. Unreadable storage is preserved, and storage failures are reported while exports remain available. Clearing browser data can remove local records.

FROM FIRST READING TO FINAL CHECK

Three field guides.

FIELD GUIDE / 01

Measure Assembly Diagonals Without Mixing References

Check a cabinet, drawer or frame with labeled diagonal endpoints, repeated readings, equal-side checks and a separate check for twist.

Read the guide →FIELD GUIDE / 02

Diagonal Tolerance and Measurement Repeatability

Interpret a diagonal difference using your project tolerance and a worst-case reading uncertainty range, with worked millimeter and inch examples.

Read the guide →FIELD GUIDE / 03

Dry-Fit Checks Before Fixing a Cabinet or Frame

Carry a diagonal reading through four physical checks, repeat after changing clamps or adding a back, and export an assembly review record.

Read the guide →