The ColumPRO 3PCS Cobalt Step Drill Bit Set is designed for serious professionals and DIY enthusiasts alike. Made from M35 Cobalt High-Speed Steel with a TiAlN coating, these step bits are built to withstand high temperatures and harsh working conditions. With a hardness of 64-67 HRC, they easily drill through tough materials like stainless steel, aluminum, and iron, making them ideal for a variety of applications. This set includes three step drill bits, each offering a range of sizes: 1/8"-1/2", 1/4"-3/4", and 3/16"-7/8". The bits are perfect for enlarging existing holes or creating new ones in hard metals and alloys. Their spiral flute design allows for fast, clean cuts while the enlarged flutes prevent chip build-up and promote rapid chip ejection, ensuring efficient operation without clogging. The tri-flat shank ensures a stable grip, preventing slipping and breakage during use, while the set's versatility allows it to work with a range of tools, including table drills, milling machines, and cordless drills. For best results, apply a cooling fluid when drilling and use a drill speed of 250-400 RPM to maximize the life of your bits. In addition to their exceptional performance, ColumPRO step drill bits are a cost-effective solution for professionals and DIYers. The set includes three heavy-duty bits, each with its own protective case, which helps keep them safe and organized in your toolbox. Say goodbye to excessive packaging and hello to a more efficient, eco-friendly solution with ColumPRO's high-quality step drill bits.