Hello all !
FreeCAD can made assembly with several workbench like A2plus, Assembly 3 and Assembly 4, you can also explode them with the addon workbench Exploded Assembly, let's try it
First example : An welded assembly made with A2plus workbench
Second example : an assembly made with workbenches : Sketcher, Part, SheetMetal & Fasteners. If a hole edge is selected Fasteners automatically place and sized up screws.