⌀

Shaft Gauge

Read diameter and length from an STL model, in millimeters

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Drop your STL file

Drag & drop or browse. Binary and ASCII STL are both supported.

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Measurement results

Load an STL file — bounding-box dimensions, length and an estimated diameter will appear here.

Length (axis)

—mm

Diameter ⌀

—mm

Shaft axis:

Axis	Size (mm)	Min	Max

Diameter (max ⌀) —

Bounding diagonal —

Volume —

Triangles —

How the diameter is found: from the distance of each point to the selected axis — the main value is the 99th percentile (rejects outliers), while "max ⌀" is the farthest point. Reliable for cylindrical parts; for irregular geometry rely on the bounding-box dimensions.

Unit note: STL files are unitless. Values are read without scaling and assumed to be in mm (the CAD convention). If your model was built in cm/inch, convert the results accordingly.