5B Heavy Duty Circle Cutter produces precision circles in sheet metal, brass, copper, soft steel, aluminum, plastic, wood, and composition materials. The high-speed steel cutting blade adjusts to accommodate the thickness of your material and features a replaceable cutting blade and a replaceable 1/4 inch pilot drill. This adjustable cutting tool will make holes or wheels from 1 inch to 6 inches (25mm – 152mm) in diameter. The 3/8” round shank circle cutter works like an adjustable hole saw but is designed for a drill press. Its maximum safe speed is 500 RPM. All adjustments are made with a hex wrench which is included. Ideal tool for making clock faces, toy wheels, birdhouses, and other projects - Great for woodworkers, model builders, hobbyists, and clockmakers. The replacement blade is General Tools Model # 4/5 Blade, replacement drill is General Tools Model # 5/6/55 Drill.