To Create a O x O Chamfer

In the graphics window, select the references from which to create the chamfer. Notice that the chamfer propagates across tangent neighbors until it encounters a break in tangency. However, if you use a One-by-One chain, the chamfer does not propagate across tangent neighbors.
Note: Press CTRL+click to select additional references for the active chamfer set or to remove a reference.
Click on the Feature toolbar or Insert > Chamfer > Edge Chamfer. The Chamfer tool opens and Pro/ENGINEER displays preview geometry. Notice that the selected references are in the References collector on the Sets slide-up panel.
Click Sets. On the Sets slide-up panel, select the Offset Surfaces chamfer creation method. Note that this is the default chamfer creation method.
Select the O x O dimension scheme from the Dimension Scheme box on the dialog bar. You can also select this scheme from the shortcut menu.
To define the offset distance, drag the distance handle to the preferred offset distance or snap it to a reference. Pro/ENGINEER displays the offset distance value in the graphics window and dynamically updates the preview geometry.
Note: You can also type a new value or select a most recently used value from the O box on the Dialog Bar. The same method applies to the distance box in the Distance table (O column) located on the Sets slide-up panel.
At this point the chamfer is complete. If you need to define the chamfer further, refer to the topics under See Also for more information.
Click to save your changes. Pro/ENGINEER creates the chamfer and closes the Chamfer tool.

Tip:

If you are using a chain as a reference and you want to modify it, click Details on the Sets slide-up panel and use the Chain dialog box.
To quickly define a distance, simply double-click the distance value in the graphics window. After the box opens, type a new value and press ENTER, or select a most recently used value from the list.
You can always select Default in a most recently used list to enable Pro/ENGINEER to determine the value.
As you work in the graphics window, you can use Clear from the shortcut menu to clear all references from the active collector.
To remove a reference from within a collector, select the reference that you want to remove, and with your cursor still in the collector right-click and select Remove from the shortcut menu.