well i have used my dremal to cut gklass before. and lets say that it really was a 50/50. i taped it all off before i stater so the glass wopuld not go all opver the place it is did crack. dont force the bit in to the glass let it do all the work. and it takes a lot of time to get the holes through. take youre time. that is all i have to say and good luck.