Bolt Lengths Calculated in OpenPlant Modeler

Hello All,

I'd like to further explanation on this:

https://communities.bentley.com/products/plant/w/plant_design_and_engineering__wiki/14484/how-are-bolt-lengths-calculated-in-openplant-modeler

If the flange thickness of the two flanges are not equal, it will use FlangeThickness X 2 or FlangeThickness1 + FlangeThickness2? Thanks a lot.