In article .com,
writes:
I have searched through previous postings and would agree that a
powered tile cutter with water bath is *probably* the way to go, BUT,
before I spend the cash can anyone suggest where I am going wrong. I
have a limited supply of expensive 300x300 floor tiles and apart from
about 20 half cuts I have a similar number where I need to take off
straight 20 - 30mm cuts. I have tried this with an angle grinder and I
find that the corners are breaking off and even one or two have
produced a smooth curved break about a third of the way in to the
cutting line.
I have obtained similar results(?) with standard stone discs and a
diamond blade. I am just curious to know if there is a particular
technique as I even made a few practice cuts on some old floor tiles
and everything was fine. I have been cutting the narrow strips first as
I can at least re-use the damaged tiles but I cannot afford the loss of
the half cut tiles as supply is a nightmare.

I cut mine with the type of cutter with a wheel which you run up
and down the glazed side a few times. It wasn't actually up to the
job, but it worked fine if you did this, and then put the tile in
the jaws of the B&W workmate with the scratch flush with the top,
and thumped it with your fist. I did lots of 20mm slices this way,
and very few broke in the wrong places. If I actually used the
wheel cutter to do the bending/fracturing of the tile (as you are
supposed to), all that happened is the tile stayed in one piece,
and the tool bent;-).

I used an angle grinder for nibbling away special shapes where
required. This would sometimes break the tile, I think through
stress caused by differential heating as it can get very hot (red
hot and more) in the area where the angle grinder is cutting.

--
Andrew Gabriel