Model-Based Definition > Model-Based Definition > Working with Model Properties > Units > Tip: Specifying Metric and Nonmetric Units
  
Tip: Specifying Metric and Nonmetric Units
When specifying your system of units, keep in mind the following guidelines:
You can specify units in Part or Assembly mode. If you are working in Assembly mode, the units for all the parts must be the same as those for the assembly.
When you enter numerical data for quantities with physical dimensions, Creo Parametric interprets the data as having units consistent with your selected system of units.
Modifying the units can invalidate your relations, as they are not scaled along with the model. Other non-parametric features, such as cosmetic, or IGES models are also not scaled with the change of units.
A part can have only one set of units.
All parts default to inches and pounds (unless otherwise set by the configuration file options pro_unit_length and pro_unit_mass).