Mechanical discipline provides with a set of standard elbow angles to apply to the elbows being used in elements hookup with ducts and pipes. The provision of selecting desired angled elbow not only saves space in the route but also minimizes the clutter in the routes.

The Stretch option saves workload of additional piece of ducts and connecting fittings to it. Rather the duct itself stretches straight in an allowable space meeting the angled elbow. This gives a clean hookup with no additional materials.

Mechanical discipline stores the default duct/pipe elbow angle properties in Autofittingoptions.xml. The angles defined in this XML file are standard angles the elbows are available in the market. The default values are; 30°, 45°, 60° and 90°. When route constraints demand angle different from these values, or where special elbows of different angles are planned the XML file can be edited to add a custom angle value.

The below procedure illustrates steps to customize elbow angle value to 75°.