Hi all, I've just got my brand new Makita 9227c yesterday. Since I'll be using only 6.5" MG pads, hence I also bought a W-64 backing plate. However, as I fit in the W-64, I couldn't turn all the way in as it's suitable for 5/8" (15.88mm)thread size. My Makita comes with a 16mm thread size (Asian version). I would like to confirm whether is it safe to be used? Thanks!