Click Exit Sketch
(Sketch toolbar).
Click Trimetric
(Standard Views toolbar).
In the PropertyManager, under Direction 1, select Through All for End Condition.
Click 
.
Cut a hole through the center of the part.
Click Exit Sketch
(Sketch toolbar).
Click Trimetric
(Standard Views toolbar).
In the PropertyManager, under Direction 1, select Through All for End Condition.
Click .
Another tool for creating holes is the Hole Wizard.
Click Top 
(Standard Views toolbar).
Select the top face of the part (see image below).
Click Centerline
(Sketch toolbar).
The centerline acts as a construction line for the Hole Wizard holes.
Sketch a vertical line through the origin.
Click Exit Sketch
(Sketch toolbar).
