This tool allows defining manually the main part of an assembly and entering the main part mark. The main part mark does not change after running the numbering process.
To access the command
Ribbon: Output > Part Marks:
Command line: _AstM4CommCreateMainPart
To create the main part of an assembly
. Connected parts (by shop welds shop bolts) can be assigned to an assembly part. The parts connected to the assembly part automatically become attached parts. A blue box object (the assembly part) is created around the connected parts
To access the command
Ribbon: Output > Part marks:
Command line: _AstM4CommCreateAssemblyMainPart
To create an assembly part
.

Example:
Stairs normally have one stringer as the main part and all other parts are attached parts. Thus, identical stringers get different marks (depending on the numbering method). The
Create an assembly part
tool (
) creates an assembly part box that becomes the main part title in the structured BOM. All parts within the blue box are attached parts and are listed with single part marks (i.e. both stringers will then have the same mark).