SAT file import as 3D SOLID but export as surface

[xxpochita123]

So I imported a 3D Solid to 3DS Max but everytime I export it as SAT file, the object changes to surface.

This is the original file from AutoCAD. 

I imported the file from AutoCAD as SAT in 3DS Max

This is the exported file (as SAT again) from 3DS Max. I opened it using AutoCAD.

[Diffus3d]

Hello @xxpochita123 ,

Body objects are technically B-splines from what I understand.   Since you don't have any conversion modifiers on the top of the stack there, the object is still just a body object with a bend on it.  If you put an Edit Poly on top and then re-export, or convert the mesh to edit poly then export, does it solve the issue?   I am not familiar with .sat files but is it a NURBS format?  

Best Regards,