The dead joint symbol is supported only by the GOST standard.
Because text and leader lines are the most common objects used for annotations, AutoCAD Mechanical toolset provides a single configuration point (the Standard Settings dialog box) enabling you to specify their default properties. These settings are the master settings.
In the Dead Joint Settings dialog box, the text and leader settings default to “By NameOfCurrentDraftingStandard.” If you modify the master settings, dead joint symbols automatically acquire the new settings. If you do not want dead joint symbols to follow the master settings, override the text height and select a specific value.