Freely from small to large diameters. No drilling required, easy to expand existing holes. Spiral blade allows for smoother drilling Uniquely developed spiral groove angle for fast biting. Constructed with minimal burr holes It uses cobalt high-speed steel, so it can be used with stainless steel. (Stainless steel: up to 1.2mm thick) Drilling, deburring, and chamfering plastic, wood and metal at the same time. You can easily create clean and clean holes with electric drills and drilling machines. It can be used to drill a variety of holes such as round pipes, square holes, oval holes, and wide objects.