Model-Based Definition > Model-Based Definition > Creating Various Annotation Types > Tolerances > Working with Dimensional Tolerances > ISO-Standard Models > ISO-Standard Models
ISO-Standard Models
The system loads the tolerance tables into the model when you create it as an ISO-standard model or switch the tolerance standard from ANSI to ISO.
To create the model as an ISO-standard model, set the configuration file option tolerance_standard to ISO. Because the tables determine how the model regenerates, the system stores them permanently with the model and you can only use them with driving dimensions.
Four types of tolerance tables are available:
General (one per model)
Broken Edge (one per model)
Holes (several per model)
Shafts (several per model)
When you create a dimension, the system assigns it to the General table. When you assign the dimension to the tolerance table, the tolerance table and its dimension value govern the tolerance values of the dimension. You can switch the tolerance table reference of the dimension to any other table.