Hi Steve, can you give the attached file a try in Alibre and see if it can recognize it any better or not?

This one is still written as a spline curve, however it has a flag set on it that tags it as a "CIRCULAR_ARC" type form.

If that seems to work better and helps Alibre to recognize it as a circle, that could be an easy adjustment for me to make.

However, it may not do the trick because Alibre may want a full "circle primitive" definition instead. Currently the library that I'm using for exporting to STEP format does not handle that so that one would take a while longer.

- Michael