10 Best Drill Bits For Hard Steel in 2026

The Bosch CO14B’s 8% cobalt M42 alloy is the key feature for anyone regularly tackling stainless steel or cast iron. That composition gives it serious heat resistance, which is critical for preventing the bit from softening and dulling mid-job. The thick web-helix design adds stability, so the bit is less likely to walk or chatter when you hit a tough spot. This set is a solid, reliable foundation for a workshop because the jobber-length bits and practical size spread handle the majority of metal drilling tasks without fuss.

The Bosch CO14B set uses an 8% cobalt M42 alloy, which Bosch states delivers ten times the life of standard bits under ideal conditions. This enhanced material and a surface-hardened tip are designed for high heat resistance and drilling tough metals like stainless steel and cast iron. For the serious hobbyist or pro who needs a trustworthy, heat-resistant bit for intermittent hard steel work, the CO14B delivers proven Bosch quality.

The TiAlN coating’s ability to handle 1472°F makes these bits a standout for anyone regularly pushing through stainless or hardened steel, where heat is the primary enemy of tool life. That extreme heat resistance, paired with an M35 cobalt core rated for 60 HRC materials, is the core of its value. It’s for the user who needs a bit that won’t blue and soften on the third hole in a tough alloy. The innovative triple-flute geometry backs this up by clearing chips more efficiently, which keeps things cooler and gives you a cleaner, more accurate hole wall.

Optimized for standard depth-of-cut applications, the aggressive triple-flute design is not intended for deep drilling where chip packing can become an issue. The Titanium Aluminum Nitride coating withstands temperatures up to 1472°F, which drastically reduces heat buildup when drilling tough materials like stainless steel. This specialized engineering is aimed at hardened metals, with an effective drilling hardness up to 60 HRC.

The Bosch CO21 set’s no-skate split-point tip is its standout feature, virtually eliminating the frustrating walk and skate that can ruin a workpiece when starting on hard steel. That accuracy, combined with the three-flat shank’s secure grip, makes this a reliable choice for a pro or serious DIYer who needs clean, controlled holes in stainless, cast iron, or titanium. The 21-piece assortment covers the most common sizes for metalworking, and the cobalt alloy is built to handle the high heat of drilling tough materials.

The Bosch CO21 set is built for tough jobs, with cobalt construction that handles abrasive metals like stainless steel. Its split-point tip prevents walking for clean starts, and the three-flat shank gives a solid grip in the chuck to resist slipping. This design focuses on control and precision when drilling into hard materials such as cast iron.

Cobalt construction makes this 29-piece set a solution for drilling hard metals like stainless steel, offering a wide size range that suits professionals and serious DIYers. Its full-sized kit fits a permanent spot in a workshop or job box, reducing trips for individual bits. In a comparative test of cobalt bits drilling stainless steel, the Milwaukee Cobalt Red line performed, while a noted non-cobalt option failed to drill any holes.

The organized case measures roughly ten by nine and a half inches, so it’s designed for a tool chest rather than a pocket. Compared to other sets, its form factor is larger overall than the more compact Bosch CO21, which is under five inches long. For quick on-site repairs with an impact driver, a dedicated hex-shank set like the NordWolf stubby bits would be easier to carry.

The promise of drilling two times faster than cobalt is the headline here, turning a frustrating chore into a quick operation on tough alloys. This speed comes from the NOMO surface treatment and tapered web geometry, which reduce friction and clear chips efficiently. It’s built for the user who needs to punch a lot of holes in stainless or titanium without constantly swapping out broken bits. The high-speed steel is engineered to flex under pressure where cobalt would fail.

Champion’s Brute Platinum drills are marketed to last three times longer than competitor bits and cut twice as fast as cobalt, which suggests a focus on endurance and speed in tough materials. Their reduced mechanics length provides added strength and rigidity, a design suited for bench work on bar stock or sheet metal. Flatted shanks aid fast chucking in keyless power tools, reinforcing the set’s role as a dedicated workhorse for steel, stainless steel, and titanium alloys.

The DeWalt Titanium Nitride set’s Pilot Point design is its standout feature, biting into the material on contact to prevent walking and deliver a cleaner hole right from the start. This makes it an excellent choice for general fabrication and shop work where precision and clean starts in hard steel are a priority, especially for users who value predictable performance over raw longevity in the most extreme applications. The tapered web and no-spin shanks are practical touches that address common frustrations, making this a reliable, well-thought-out set for steady use.

DeWalt’s Titanium Nitride coating is designed for longer bit life, which means these drill bits should maintain their cutting edge through more projects before needing replacement. The pilot point design starts on contact for cleaner holes, so you’re less likely to have the bit wander off your mark. No-spin shanks also help keep the bit secure in the chuck, reducing slippage during use.

A 5% cobalt alloy formulation gives these bits serious staying power when the chips get hot, which is exactly what you need for drilling into hardened steel without constantly stopping to cool the bit. The heavy-duty web and split-point design mean you can start a hole accurately and push harder without worrying about snapping, making it a reliable workhorse for a shop that sees a mix of projects.

The trade-off is the substantial footprint of the case, which is over a foot wide. That’s fine for a permanent spot on a workshop shelf but less convenient for a crowded mobile toolbox compared to a compact set like the Bosch CO21.

The M35 cobalt construction is the key here. That 5% cobalt content lets these bits handle the heat generated when drilling into hardened steel or stainless without immediately dulling, which is exactly what you need for tough materials. For the hobbyist or occasional user who needs to punch holes in metal without breaking the bank, this set covers the essential sizes from 1/16″ to 3/8″ in a straightforward, jobber-length format. The 135° split point starts cutting quickly and helps keep the bit centered, so you spend less time fighting wander marks on your workpiece.

The trade-off is in the scope. With 15 pieces, you get a solid foundation, but you won’t have every fractional size a professional might reach for daily. Compared to a larger, more comprehensive kit, you’re getting a focused toolkit rather than a complete shop solution. The round shanks work fine in standard chucks, but they don’t offer the grip of a three-flat shank when you’re really cranking down the torque. For most garage projects, however, this set delivers the core performance needed to get through hard steel reliably.

A maximum length of just over two inches is the defining feature here, letting you get a drill into spots where a standard-length bit simply won’t fit. This set is for the mechanic working on a cramped engine bay or the fabricator adding a hole to an assembled frame. It suits any situation where clearance is measured in fractions of an inch. The M35 cobalt steel and 135-degree split point are built to start biting into stainless and hardened steel without walking. The hex shank lets you pop them into an impact driver for stubborn fastening jobs in the same confined areas.

A trade-off for the ultra-compact design is a limited selection of five imperial sizes, ranging from 3/32″ to 5/16″. This makes the set a specialized solution for confined spaces rather than a primary workshop collection. When clearance is minimal and the material is hard metal, these stubby bits are the tool designed to fit and function.

The 135-degree stepped split point is the key feature here. It bites into hard steel with less ‘walking’ and requires less pressure to start a fresh hole, which translates to less user fatigue and more precise drilling. This set is built for the fabricator or mechanic who frequently needs to open up existing bolt holes or create clean, new passages in tough materials like stainless steel. The gold oxide finish isn’t just for looks; it helps dissipate heat, extending the life of the cobalt steel when you’re pushing hard.

This set’s stepped point design is specialized for enlarging existing holes and starting new ones more easily in materials like acrylic and hardened metals. For drilling many deep, fresh holes in thick plate, a more dedicated choice might be a set with a three-flat shank designed for demanding metalwork. The Drill America kit organizes a comprehensive range of sizes from 1/16-inch to 1/2-inch into one round case for the workshop that values a single set for sizing and finishing holes.