Thermoset Coating provides up to 2X Faster Cuts. Bi-metal construction with 8% cobalt for increased wear resistance. Drills through wood, plastic, aluminum, metal. Most Durable Hole Saw. New 3.5 TPI Tooth Design. Customizable Hole Saw Case. The MILWAUKEE 21-Piece HOLE DOZER Bi-Metal Hole Saw Kit features RIP GUARD, the strongest tooth form. They’ve built the hole saw blade teeth with more steel behind the cutting edge for added strength. This added tooth strength combined with 8% cobalt, gives added life to the teeth, providing users with increased productivity on the jobsite, as well as consistent hole quality. This Milwaukee hole saw blade set includes Plug Jack, an all-access slot that provides access lower into the cup for thick material and higher towards the teeth for thin material for plug removal. The Plug Jack increases productivity and eliminates wasted downtime between holes with multiple positions to apply leverage and better plug access. Drill Bit Type: Hole Saw. Drill Bit Type(s) Included: Bit Extender/ Holder, Brad/Pilot Point, Hole Saw. Min Chuck Size Required: 3/4 In. Number of Pieces: 21. Pilot Bit Included: Yes. Teeth Per Inch: 4/5. Tools Product Type: Power Tool. Drilling Depth (in): 1.8.