CrazyPiercing 00823A Shank Heavy Duty Diamond Dust Hole Saw, 1/4-Inch, 5-Piece, Hole Saw Sizes: 5/16 Inch 5-piece diamond dust hole saw with 1/4-inch shank, 5/16 hole saw size Hole Saw Sizes: 5/16 inch,1/4-inch shank The diamond coating on these saws give superior performance and life Set is ideal for drilling clean and accurate holes Excellent results in granite, ceramic, porcelain, glass, marble, slate, and tile.