This option is used when a circle or arc (part of a circle), generated by a CAD system, has been imported into 3DCS. This option creates a Coordinate Point at the center of the CAD circle and also converts the CAD circle to a 3DCS type circle. Once the CAD circle has been converted to a 3DCS type circle, it can be used to represent a pin or a hole.
Procedure:
•Put the parts of the assembly in the separated position.
•Click on Geometry 
Create 
Convert CAD Circle. This brings up the Click Graph window dialog displaying Convert CAD Circle.
•Click on the desired CAD circle or arc.
•A window will pop up warning you that the parts must be in the separated position, and asks if you wish to convert the chosen circle. Click Yes.
•Another warning window will appear asking if you would like the original CAD circle deleted when creating the 3DCS type circle. Click Yes to delete it or No to save it. Saved CAD circles may be useful for later modeling, however they will not display any size variation.
•The circle will then be converted and a point will be created at the center of the circle. 3DCS will assign an initial name to the point. It can be renamed using the Edit Point dialog box.
Notes:
•After this circle has been created, the user may modify the circle like any other circle created in 3DCS. Use Modify Circles to change the circle's parameters such as size, direction, size tolerance, material condition, designate hole or pin type, etc.
•Many CAD entities which appear to be circles, may be slightly elliptical or simply just drawn as round looking lines. If Convert CAD Circle fails to identify a round CAD entity as an actual circle or arc, it may be necessary to use the Modify CAD Entities function to first create points around the perimeter of the circle, then create the centerpoint from those points.