Why this small difference in cylinder diameter?

[terrypin 3]

The images show a (partial) cylinder with a test height of 2 mm, before I increase it to the eventual 20. I need precision because it has to slide over an existing object. I'm puzzled by the small discrepancy between OpenSCAD showing the diameter as 26.0 mm and Cura (after slicing) reporting 25.5 mm.

 

EDITED to show another example.

 

Terry, UK

Edited November 11 by terrypin

[ahoeben 2,011]

You mean the 25.5 in the lower left corner?

 

29.0 x 25.5 x 2.0 is the dimension of the bounding box of the models in the scene. Cura does not know or report the inner diameter of your model.

[terrypin 3]

Thanks. That explains it!

 

My additional example passed yours in the ether 🙂