hi,

blender 2.74 will be able to import and use the normals as
generated by the CAD soft.

http://wiki.blender.org/index.php/User:Mont29/Foundation/Split_Vertex_Normals/Custom_Split_Normals_Manual

i show you a test with a nigthy build

https://builder.blender.org/download/


the outlined object use the new improvement => no bad artifacts