General Tools 4 Circle Cutter, Adjustable 7/8-Inch to 4-Inches From the Manufacturer Combination round and square shank circle cutter that acts like an adjustable hole saw for use with drill press or bit brace. This tool has replaceable 3/16" high speed steel bit and replaceable 11/64" pilot drill with maximum safe speed of 500 RPM. Sizes: 7/8" to 4"; 3/8" round shank. Features General Tools circle cutters produce precision cricles 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; Features a replaceable cutting blade and a replaceable 1/4 inch pilot drill This quality cutting machine will make circles from 7/8 inch to 4 inches in diameter; Maximum safe speed is 500 RPM, for use with a drill press only This round shank circle cutter is great for making smooth cuts through most materials, including wood, composite, sheet metal and more; Shank is 3/8 inch round All adjusments are made with a hex wrench which is included; Replacement blade is General Tools Model # 4/5 Blade USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.