To Place a Torus Surface

Select the Torus Surface tool ( Modeling > Surfaces > Create Surfaces > Primitive Surfaces > Torus ).

Enter a data point to define the start point.

Enter a data point.

Primary Radius:	This data point defines:
Off	Center, primary radius, and start angle.
On	Just the center and start angle.

Enter a data point to complete the torus, as follows:

If these are on:	This data point defines:
None (Primary Radius has no effect on this step)	Secondary radius and sweep angle.
Secondary Radius	Sweep angle.
Angle	Secondary radius.
Secondary Radius and Angle	Direction of the sweep angle rotation.