I’m a industrial designer and found Blender last year and I was using Alias for 20 years. Blender has best UI so far. I never see other cad software (include Alias) has such as great detail approaching in visul appealing even in wireframe mode… anyway, great tool for concept development and visualization. But my clients or vendors they all need to get my models for some cad work for their end. But I only can export obj, stl or fbx, which they can not do any modification. even very simple sheet metal design…so I have to redo everything in Rhino… I’m deeply hope blender can support exporting iges and step. and I think blender will not just game changer it should be Endgame 
, well, at least at Industrial design field…
I might be wrong but since iges and step are not polygon based formats I don´t think it is possible to export to them. At least not in any way that the resulting data would be useful for further modification.
Some tips that I discovered by chance here, I hope in near futures someone develop something similar that has Freeship for Blender surfaces, but for now look that. From Blender Subdivision To N.U.R.B.S. (IGES) for free
thanks for reply and I’ll check out the moi…I also see other blender guys use fusion T-spline is any different? thanks for the informarion