Last sunday, since the drill was out of its case, and I got 6mm and 8mm lugs the day before, I tried to make a 6mm lug into a 7mm to fit the Grid Tie Inverters' terminals ...
It did not work as planned: I bent the lug big time during the drilling and realized that the copper was - of course - showing once the hole had been drilled all the way, which in time might bring corrosion and a loss in conductivity
6mm lug drilled to 7mm
It fits now perfectly onto the 7mm terminals of the GTI
6mm, 7mm, 8mm
6mm does not fit
8mm is loose