Drilling through hardened steel is no easy task. The material’s density and strength can quickly wear down ordinary drill bits, leaving you frustrated and stuck mid-project. So, what’s the solution? You need the right tools built specifically for the job. That’s why we’ve tested and reviewed the best drills for hardened steel—so you don’t have to waste time or money on options that simply won’t perform.
But here’s the catch… not all drills are created equal. Some excel with wood or softer surfaces, while others rank among the best drills for metal or even the best drills for concrete. The key is knowing which features make a drill truly capable of cutting through hardened steel with precision and durability. Ready to find out which models deliver the power you need? Let’s dive in!
Top pick
Best Durability: DEWALT Titanium Nitride Coated Drill Bit Set
The DEWALT Titanium Nitride Coated Drill Bit Set comes with 21 pieces ranging from 1/16 inch to 1/2 inch. The titanium nitride coating helps extend the life of the bits, while the Pilot Point tips start on contact to create cleaner holes. The no spin shanks improve stability during drilling, and the tapered web design reduces the chance of breakage. A tough plastic case keeps the set organized and portable.
From a customer perspective, users value the sharpness and accuracy these bits deliver, especially for wood, plastic, and softer metals. Professionals appreciate the reduced walking when starting holes and the durability of the coating, though some note performance limitations with harder materials.
Overall, this set provides reliable performance and long-lasting value for general use, making it a solid choice for homeowners and professionals who frequently work with standard materials.
Best for Stainless Steel: BOSCH CO14B 14-Piece Assorted Set
The BOSCH CO14B 14-Piece Cobalt M42 Drill Bit Set is built for demanding metal applications. Made with 8% cobalt alloy, these bits are designed to last up to ten times longer than standard bits. The M42 cobalt construction offers excellent heat resistance, while the surface-hardened tips penetrate stainless steel, cast iron, and titanium with efficiency. The thick web-helix structure adds strength and stability during heavy-duty drilling. A sturdy case is included for organization and portability.
From a customer perspective, this set is well-regarded for its ability to handle tough metals without dulling quickly. Professionals appreciate the balance of durability and precision, particularly in high-temperature environments. However, some users note that the set offers fewer size options compared to larger kits, and the premium quality comes at a higher cost.
Overall, the BOSCH CO14B is a reliable and durable option for users who frequently drill into stainless steel or other hard metals, offering excellent performance and long-term value despite the smaller assortment.
Best for Hardened Steel: Crosstar M35 Cobalt Drill Bit Set
The Crosstar M35 Cobalt Drill Bit Set is designed for high-performance drilling in hardened steel, stainless steel, and cast iron. Made from M35 cobalt steel with higher cobalt content than standard bits, it delivers superior hardness and cutting strength. The titanium aluminum nitride coating enhances heat resistance up to 1,100°F, extending lifespan and reducing friction. A 135° split-point pilot tip ensures accurate starts without walking, while the spiral flute design clears chips efficiently. The set includes 21 jobber-length bits with duplicates of common sizes, all stored in a durable shockproof case with clear labeling.
From a customer standpoint, this set is valued for its precision and consistency in demanding metalwork, particularly in automotive and fabrication settings. Users note the smooth drilling performance and reduced bit breakage, though results may vary with extremely hardened alloys.
Overall, the Crosstar M35 offers excellent performance for professionals and advanced DIYers, combining strength, accuracy, and efficiency in a well-rounded kit that balances durability and versatility.
FAQs
What is the best drill bit for hardened steel?
The best drill bits for hardened steel are typically cobalt drill bits. Made from high-speed steel with 5–8% cobalt alloy, they are extremely hard and can withstand the heat generated when drilling tough metals. Unlike standard bits, cobalt bits hold their sharp edge longer and resist wear under heavy-duty use. Carbide-tipped drill bits are another premium option, offering excellent hardness, but they can be brittle and more expensive. For most DIYers and professionals, cobalt drill bits strike the right balance between durability and cost-effectiveness.
What is the best technique to drill hardened steel?
Drilling hardened steel requires precision and patience. First, always mark the spot with a center punch to keep the bit from wandering. Then, apply steady pressure without forcing the drill—let the bit do the cutting. Use a cutting fluid or lubricating oil to reduce friction and heat, which prevents the bit from dulling too quickly. Start with a smaller pilot hole before moving up to the desired size. Finally, keep the drill stable and straight to ensure a clean cut.
What drill speed is best for hardened steel?
When drilling hardened steel, slower is better. High speeds generate excessive heat, which can quickly damage the bit and the material. A general rule of thumb is to keep the drill speed under 500 RPM for larger bits and slightly higher for smaller ones. Using a variable speed drill allows you to maintain better control and adjust the pace depending on the bit size and thickness of the steel. Remember—cooling and steady pressure are just as important as speed.
Are cobalt or titanium drill bits better for hardened steel?
For hardened steel, cobalt drill bits are the superior choice. Titanium-coated bits are designed for softer metals and wood; while they are sharp and durable at first, the coating wears off over time, leaving them less effective against hardened steel. Cobalt bits, on the other hand, are made from solid alloy throughout, so their cutting performance remains consistent even after extended use. If you plan to drill hardened steel regularly, cobalt is the clear winner. Titanium bits are best reserved for lighter, less demanding applications.
Conclusion
Drilling into hardened steel is one of the toughest tasks for any DIYer or professional, but with the right tools, it doesn’t have to be frustrating. The best drills for hardened steel are those built with strength, heat resistance, and precision in mind. Choosing a quality cobalt or carbide-tipped bit, pairing it with proper drilling techniques, and maintaining the right speed can make all the difference in performance and longevity. Ultimately, the best option depends on how often you’ll be working with hardened steel and the level of accuracy you need. By investing in reliable drill bits and applying the correct methods, you’ll save time, reduce wear, and achieve cleaner results on every project.
