Some will cut and some won't, but you never know until you actually try the tile. Make sure your height adjustment is bang on and that the wheel is in good order. Weaken the scored tile at the top end first by applying enough pressure with the handle so you can start to hear or see the glaze crack then stop and go back to the bottom of the tile and break as normal, should do it ok. In some cases its better to do a bit of 'Bruce Lee' on the tile, instead of using the handle to break the tile use your two palms and punch down equally on both sides of the tile while its on the machine after you've scored it a few times 😉