Hi, I've borrowed my Dad's old Performance Power FMTC550TC electric tile cutter and the blade is pretty blunt. I'll be tiling around my bath with 60×35×9cm porcelain tiles - which 180mm blade would you recommend?
What is the blade you are trying to use rated for?
If it is for regular white body tile is most likely to hard for porcelain.
Remember the harder the material, the softer the blade. The blade needs to break down to expose new diamond, a hard blade used on a hard material will not break down.