CCAD
Steel Shapes for AutoCAD
Trial versionAutoCAD Tool for Drawing Steel Shapes
WindowsWeldsym
Trial versionAutoCAD Tool Simplifies Welding Symbol Creation
WindowseDucts
Trial versioneDucts Simplifies Round Ductwork Design in AutoCAD
WindowsPfast
Trial versionPfast 2.1: Streamline Hole and Fastener Creation in AutoCAD
Windows