How much gap do you allow between piece parts for weldments? Is it dependent on material thickness, is there a rule of thumb or some industry method for determining it?
In my work in a (mostly) fabrication shop, I design many weldments. I don't leave any gap between parts. Weld preps such as bevel grooves or V grooves are specified as required.
I never really showed the gap I would make the assembly drawing with the end result in mind. But mostly because the shop knew how much gap to use depending on the weld call out.
There will be some natural gaps in some cases. If you are welding sheet metal, the correct way to model will be to have the inside edge of one sheet meet the inside edge of the other sheet. This will leave a natural gap to fill with weld.
