Learn the difference between standard and custom steel framing families.
Placing structural connections between steel beams, braces, and columns is dependent on a number of parameters of the elements in the connections. The Structural Section Geometry group of parameters in the Type Properties dialog list these dependent parameters. In most cases, the required parameters are readily available from stock Revit libraries. In customized framing elements, the geometry parameters for connections may not exist and must be generated. Because of the importance of the structural section parameters in generating connections, Revit must understand if a family is standard or custom.
- Standard structural steel element. The Section Shape type property of a steel framing element specifies a section shape. A defined set of Structural Section Geometry parameters exists for the element.
- Custom steel element. The Section Shape type property of a steel framing element is Not Defined. The geometry parameters required for generating steel connections are not defined.
In some cases, custom steel element families may still accept connections if it has well defined family geometry. Revit will analyze the family and attempt to identify its section shape. The recognition methodology examines the family geometry and tries to match its section to common steel section shapes.
Once matched, Revit generates the necessary structural section geometry from the defined family geometry. Steel connections then generate using these parameters passed on by the Revit API. The following shapes are supported for matching if their Section Shape parameter is set to Not Defined.
| Section Type Symbol | Section Name | Shape |
|---|---|---|
| I | Double Tee | 
|
| C | Channel - Cold Formed | 
|
| U | Channel | 
|
| W | Angle | 
|
| T | Tees | 
|
| H | Rectangular Pipe | 
|
| S | Round Bar | 
|
| R | Pipe | 
|
| CEx | Channel with Fold - Cold Formed | 
|