The following points are important for bolt thread modeling:
The Bolt cylindrical surface/edge should be the contact side.
Starting Point and Ending Point of bolt thread (under Bolt Thread Correction), should be on the bolt axis and defined in the global coordinate system.
In order to achieve better accuracy, the mesh size in the thread region should be less than the Pitch Distance.
We recommend using the projection-based contact Detection Method (Nodal-Projected Normal From Contact).
This technique is valid only for standard, straight threads. It is not applicable for nonstandard threads such as tapered threads or buttress threads.
The maximum stress in the thread region may vary with mesh density. However, the overall stress distribution remains similar in pattern.