Bahco 3830-140-VIP Bimetal Hole Saw with Industrial Packaging and 5-1/2-Inch Diameter 5 1/2-Inch holesaw Combines a flexible shatter resistant spring steel back with a high speed steel cutting edge Cutting edge features 4 to 6 teeth per-Inch and is an electron beam welded to a tough alloy back Teeth are precision ground to further increase cutting efficiency Cuts clean, accurate holes in virtually any machinable material