See also : CADLine dialogbox
MechDesigner has three sources for its MassProperties:
•  MassProperties that are userdefined on the CADLine. 
•  Mass Properties imported to a CADLine with a SolidWorks document. 
•  Mass Properties that are derived from Profile/Extrusions on a Part 
Separators


If you enter MomentofInertia, then with the Mass, MechDesigner calculates the equivalent RadiusofGyration If you enter RadiusofGyration, then with the Mass, MechDesigner calculates the equivalent MomentofInertia Parallel Axis Theorem MechDesigner uses the Parallel Axis Theorem to calculate the MomentofInertia, Io , about the Part's rotational axis: I0 = IG +M.h2 where h is the distance from the CentreofMass to the rotational axis 
When you import a SolidWorks document onto a CADLine, you can also import the SolidWorks MassProperties 

Button IMPORT / UPDATE Mass Properties FROM THE ACTIVE SolidWorks DOCUMENT Make sure that the SolidWorks' active document is the model on the CADLine.
Button Remove SolidWorks Mass Properties

Total Mass Properties: The Total Mass Properties for ALL CADLines in one Part. EXPLICITLY: the Total Mass Properties include, for each Part, ALL of those:


NOTES: ParallelAxis Theorem Inertia about Part's RotationalAxis = Total Inertia about CentreofMass + Mass × (Distance to Part's RotationalAxis)2 Relationship between MomentofInertia and Radius of Gyration Total Inertia (about CenterofMass) = Total Mass × (RadiusofGyration)2 Total Mass of Part = Mass of all Extrusions + Total mass of other CADLines in the same Part Total Inertia about the Part's CentreofGravity = Inertia of all Extrusions + Total Inertia of other CADLines in the same Part 