Notes: 4x4 wood beams' actual size depends on the wood type and dryness. We made internal size 3.6x3.6inch of this 3-way corner bracket according to the general size of wood. We believe that beams actual size larger than 3.5inch is in very rare cases. Once this happens, we can try sanding and triming the wood beams, to match with the inner size of the corners. But if we made the conners' size larger than 3.5inch, there will be a gap between wood beam and the conner wall, which is difficult to fix.