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.

Thanks

Ken