It is supposed to cut it as is with the blade provided.
Hello Charlie. Porcelain tile 3/8" thick are one of the hardest material to cut and for that reason, we would recommend you a cuter with more breaking strength such as the Speed24 (http://www.homedepot.com/p/Rubi-Speed-24-in-Tile-Cutter-13961/203352144). If you are having problems with Practic tile cutter, try to score 2 inches backwards at the end of the tile and then score forward from the edge all the way to the top. Also try to score twice. If you still have problems, please give us a call at 305 715 9892 and we will guide you over the phone. Thank you!
A wet saw will cut slate like butter.
We did glass tiles and it scores it then just tap it and it breaks where u cut it. Our kitchen turned out nice just don't work as well if u only need a very small bit off
My Home depot sells the cutting wheel assembly for about $16
The cutter is warranted for two years. Call the manufacturer. I am sure they will be happy to help you.