Hi Steve - yeah it looks like currently when MoI writes the step file it writes the circle as a spline curve type.

Often times if it is important for a receiving application to handle circles in a special way, they can check to see if the spline curve is the standard kind of spline curve that makes a circle, and flag it as being a circle primitive at that point. But it sounds like Alibre is not doing that kind of shape detection in it.

Could you please post an example file with a circle in it saved out from Alibre so I can see how it prefers to have circles structured in the STEP file? I'm not sure yet if I will be able to do much about that but it may be possible for me to adjust that.

- Michael