There is only one file type that uses the .MC9 extension:
Mastercam 9 Geometry File
Data format used by Mastercam 9 CAM (Computer Aided Manufacturing) software; may contain 2D and 3D geometry and toolpath data that defines areas to be cut by a machine; used as templates for mills, lathes, wire cutters, and routers.
|CNC Software Mastercam 9|
Updated: October 16, 2007