Diamond-Plus Grit Hole Saw is 1-1/4 inch, with a Shank Size of 3/8 inch is designed for drilling perfect holes in hard materials such as porcelain, hard tile, quarry tile, granite tile, and glass. The slot in the hole saw provides easy plug removal while the vacuum-brazed grit ensures long life. Use with low RPM and minimal pressure. For cool cutting lubricate with water for extended life.