Sandflex Bi-Metal Hole Saws - Sandflex® Bi-metal hole saws perform excellently in most materials such as wood, plastic, non-ferrous and ferrous steels including stainless steel. They are suitable for electric drills, both stationary and portable. Side slots allow for quick and easy removal of the cores. Maximum cutting depth is 38 mm (1 1/2"). 4/6 teeth per inch. All C-hole saws come in retail packaging with instructions that also serve as tooth protection. Max. hole size = nominal hole saw size + 1.5 mm / - 0.0. Extra large sizes: 168 mm and 210 mm with 6 TPI and standard cutting depth. 177 mm with 4/6 TPI, maximum cutting depth of 50 mm. All large hole saws cut with a 0° cutting angle for a less aggressive cut.