4.3 Datums

You'll often need references like planes, points or axes when using features for creating geometry. Often you can use present elements within the existing geometry of your model.
If the necessary references are not present, you'll have to create them.
These references, only used for creating features, are called datums.

Usually you can use the following datums: (refer figure "Plane for tilted hole")

Points
Axes
Planes

Attention:

Datums are not recognized as elements for construction, if they are used efficiently. Like when creating elements for construction, datums should always be created relatively to other elements, and not absolutely. You can control if you have properly positioned datums by just changing the dimensions of your base body.