Model-Based Definition > Model-Based Definition > Creating Various Annotation Types > Tolerances > Working with Dimensional Tolerances > Dimensional Tolerance Basics > System and User-Supplied Tolerance Tables
System and User-Supplied Tolerance Tables
The configuration file option tolerance_table_dir sets the default directory for a user-defined tolerance table. All Holes and Shafts tables overwrite existing tables when loaded.
When loading General and Broken Edge tables, keep in mind the following:
If you load one table that has the same set of class names as the model, the system accepts the new table.
If you load a table that contains class names that conflict with those already loaded in the system, the system does not load those class names.
If you load two tables with class names that do not conflict with those in the system, but that are different from them, you overwrite the ones in the system.
If the default class of the model does not exist in the new names, you must specify a new class.
After you load the new tables, the system assigns the new dimension tolerances. When you regenerate the model, the system reassigns all the tolerances of the dimensions from the tolerance tables. If you modify a dimension tolerance, it deletes the tolerance table reference for that dimension, and the tolerance value remains the same until you modify it again or reassign the tolerance table.