MIBRO's bi-metal hole saws feature a 1-3/4" cutting depth that cuts through a 2 x 4 in a single pass. The 4/6 variable tooth pitch allows for safe and efficient cutting through metal, plastic, and wood. M3 high-speed steel teeth are electron-beam welded to blade body for strength and consistent quality. Hole saws are vacuum heat treated for consistent blade hardness. They feature a thick heavy-duty backing plate for rigidity and cutting support when cutting uneven surfaces. Our EZE Slot design allows for quick and easy plug removal on all blades with a diameter of 1-3/4 in (44.45 mm) and larger. Set includes six hole saws and one screw-in mandrel and pilot drill. See label for cutting depth and cutting speeds for different materials.