Richard J Kinch wrote:
Chamblin writes:

We have a porcelain tile shower and need to attach handicapped grab
bar. How do we drill this tile? Diamond bit?

Diamond.

Good porcelain will ruin a carbide bit before you finish the first hole.
Then you have no hole, and no bit.

I have drilled porcelain tile with a carbide bit, and it did not ruin
the bit. Once the bit gets started into the hard surface, it goes
nicely.
Even if the bit is "used" by the hard service, it is cheap to replace if
needed. My carbide bits seem to last forever, and they are the cheap
ones, too. --Phil
--
Phil Munro Dept of Electrical & Computer Engin
Youngstown State University
Youngstown, Ohio 44555