COZERI 20PCS Metal Cobalt Drill Bit Set - 3mm, 4mm, 5mm Gold Twist Drill Bits for Stainless Steel, Hard Metal, Cast Iron, Copper, Aluminum, Wood HSS Twist Cobalt Drill Bits Set Bosch-Compatible

• 【20PCS Set】Comprises 10pcs 3mm drill bit, 5pcs 4mm, and 5pcs 5mm cobalt drill bits—this cobalt drill bit set offers a well-rounded size assortment to handle various drilling tasks. Compatible with pillar drills, handheld electric drills, battery-powered drills, CNC machines, and even Bosch drill bit set setups.
• 【Cobalt HSS】Crafted from high-speed steel with cobalt, these metal drill bits are heat-quenched for exceptional wear resistance and toughness—ideal as steel drill bits for hard steel, tackling stainless steel, cast iron, and more.
• 【135° Self-Centering】Professional tips on these drill bits for metal eliminate pre-drilling/center punching, ensuring precise, non-walking starts. Drills quickly with less pressure, clearing chips faster for efficient work.
• 【Multi-Material Use】Perfect for hard/soft metals (stainless steel, aluminum, copper) as reliable metal drill bits, plus plastic and wood—an all-purpose cobalt drill bit set for professionals, DIYers, and home improvement enthusiasts.
• 【Easy to Use】These cobalt drill bits require maintaining perpendicular alignment and cool operation for optimal performance. Controls heat and speed effectively, ensuring smooth drilling in various materials, from steel to wood.

featuring 10pcs 3mm, 5pcs 4mm, and 5pcs 5mm twist drill bits, designed as professional metal drill bits for hard steel, stainless steel, cast iron, copper, aluminum, plastic, and wood. A must-have accessory for both pros and DIYers, these metric straight shank bits deliver reliable performance across diverse materials. Crafted from high-speed steel infused with cobalt, these drill bits for metal undergo high-temperature quenching to achieve exceptional wear resistance and toughness. Whether tackling rigid stainless steel or soft aluminum, they stand up to heavy use without losing sharpness, making them a durable addition to any tool kit—comparable in quality to trusted sets like Bosch drill bit set. Equipped with 135° self-centering tips, these cobalt drill bits eliminate the need for pre-drilling or center punching. They pierce metal plates quickly with minimal pressure, preventing "walking" during use and clearing chips and debris efficiently, ensuring smooth, precise holes every time. Package Includes: 10pcs 3mm drill bit, 5pcs 4mm drill bit, 5pcs 5mm drill bit. Compatible with a range of tools, including pillar drills, handheld electric drills, battery-powered drills, and CNC machines, offering versatility for any workspace. How To Use: For best results, keep the drill bit perpendicular to the work surface and maintain proper cooling during operation. Adjust speed and monitor heat when drilling through hard metals to preserve bit sharpness. Perfect for professionals, home improvement enthusiasts, and DIYers seeking a reliable cobalt drill bit set for all their metal and multi-material drilling needs.