The 3-piece blade is designed to prevent chips from falling off even when used hard. It can be used to drill curved surfaces from thick steel plates to thick metal pipes. The blade design is designed to reduce friction, making it lighter, faster and longer lasting than conventional products (flat blades). The use of a step center drill reduces impact during center drilling. The drill chuck diameter is used as a shank, 0.4 inch (10 mm) / 0.5 inch (13 mm) chuck.