Built with premium cobalt-infused steel, this step drill bit delivers industrial-grade durability—perfect for tackling tough metal drilling tasks. The cobalt composition boosts heat resistance and wear resistance, letting you drill through stainless steel, high-carbon steel, aluminum, and even hard plastics without overheating or dulling quickly. Unlike regular HSS bits, it maintains sharpness through repeated use, cutting down on replacement costs for both DIYers and pros.​ Each drill bit in this set features a unique stepped size design， that fit the vast majority of everyday drilling needs，Each step is laser-marked for easy size identification, so you can switch between hole sizes quickly without fumbling for multiple bits. The 1/4-inch hex shank fits most impact drivers and drills for stable, slip-free operation—great for both handheld jobs and bench work.​ Its split-point tip starts drilling on contact, no pilot hole needed, saving time and reducing metal burrs. Whether you're installing hardware, working on automotive repairs, or fabricating metal parts, this cobalt step drill bit balances power and precision to get the job done right.