When you select the drafting standard (and the revision), the default settings for edge symbols change to match that drafting standard.
If necessary, you can customize these settings to suit your drafting requirements.
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 Edge Settings dialog box, the text and leader settings default to “By NameOfCurrentDraftingStandard.” If you modify the master settings, edge symbols automatically acquire the new settings. However, if you do not want welding symbols to follow the master settings, you can override the text height and select a specific value.