Within the Global Database we can access the Stiffeners dialogue to create and setup new Stiffener types.
To gain access the Stiffeners, Navigate to Database 
Fittings
Stiffeners.
With each creation, you can specify whether the stiffener is to be used for internal, external or both types of stiffening. There are additional options to specify whether each type of stiffeners will be positioned at the center of the duct or at each end.
To create a new Stiffener click the 
icon in which you can give a name for the stiffener.
Using the drop down for Central Type and End Type, we can make the selection for where the stiffeners are to be positioned. Setting this option to None will result in no stiffener being present for that type.
External type = Is used primarily for flange type stiffeners that will calculate lengths of stiffener based on the periphery of the duct. Example stiffener types are shown below. Central type shown in GREEN and End type shown in RED.
Internal type = Is used for internally stiffening with tie rods and can be used to specify hole placements for the tie rods when manufacturing. The software can additionally cut these holes when the stiffener is applied to the duct at takeoff. Tie rods shown in GREEN are Internal Central type and RED are End type Internal tie rods.
Both = Both External flange type and internal tie rods can be specified to be used either centrally or at the end of the duct dependant on application of each type via the breakpoints. Please view the Stiffener Breakpoints topic for how to configure.
Adjustments can be made to the Long and Short sides of the stiffener for example a 500x500 duct would require a slightly larger External stiffener to wrap round the periphery of the duct. Setting the Adjust fields to 80mm each on Long and Short sides will result in your total stiffener length being 2.32m ((4 x 500mm) + (4 x 80mm)).
The LS Only parameter can be set if only wanting to calculate the total length of stiffener based on the largest side. This option for example if set with a value of 500mm and the duct size for the stiffener application is 800x400, will result in the short side (400mm) being taken out of the calculation for the total length. The result being 2 x 800mm stiffeners equalling 1.6m total length ignoring any adjustments in this case.
External stiffener used with LS Only option shown above in GREEN.
After the stiffener types have been determined, Stiffener Breakpoints can then be setup. For information on how to setup your stiffener please read the Stiffener Breakpoints topic.