10 Best Drill Bits For Thick Steel in 2026

The 5% cobalt alloy is the key here, offering significantly higher heat and abrasion resistance than standard high-speed steel. That’s what lets you push through thick steel without prematurely blunting the cutting edge. Combined with the 135-degree split point to keep the bit from skating on curved surfaces, this set delivers the core performance needed for serious metalwork. It’s the logical first choice for anyone who needs a reliable, comprehensive set of bits that can handle the heat and punishment of drilling steel regularly.

Unlike some other cobalt sets, such as the Crosstar M35, this one does not include a TiAlN friction-reducing coating. For general metal drilling, the cobalt alloy’s properties are the primary feature. The set’s heavy-duty web construction is noted for added strength and durability.

An 8% cobalt M42 alloy gives these bits their serious heat resistance, which is exactly what you need when pushing through hardened steel or stainless without constantly quenching. The surface-hardened tip and thick web-helix design are built to prevent wandering and breakage under heavy pressure. This set is a solid, focused choice for a fabricator or mechanic who regularly encounters tough alloys and wants a durable bit from a trusted brand, without needing a massive assortment of sizes.

For drilling tough metals like stainless steel and cast iron, the Bosch CO14B set uses an 8% cobalt alloy that Bosch says lasts ten times longer than standard bits. This M42 material provides high heat resistance, which helps the bits maintain their edge during demanding applications. While a generic Bosch cobalt bit was noted in one test for a specific performance level, this set’s thick web-helix design adds stability when pushing through hard, abrasive materials.

Champion says these bits can drill three times longer than competitor bits, which points directly to their durability. The Brute Platinum set is built for shops that regularly work with stainless steel and titanium alloys, where a broken bit means wasted time and material. Its self-centering split point and tapered web geometry deliver on the ‘drill accurate’ promise, letting you hit your mark on curved or hardened surfaces without a pilot punch. This set suits anyone who needs a tool that can take repeated punishment in thick steel without chipping like cobalt or flexing too much.

The reduced ‘mechanics length’ gives these bits added strength and rigidity for tough materials, a trade-off that limits drilling depth compared to standard jobber-length sets. This makes the set a beast for through-holes in plate or structural steel, but you’ll feel the constraint in deep cavities like I-beam webs. While general cobalt bits can chip or snap, the Brute Platinum’s high-speed steel is designed to flex under stress according to the manufacturer.

The 135-degree stepped point is the key feature here. That geometry bites into the material with less pressure, which makes starting a hole in thick steel plate far less of a fight. It’s a smart design for anyone who regularly needs to enlarge existing holes or drill fresh ones in acrylic and hardened metals without the bit skating. This set suits a professional who values a bit that gets to work quickly and lasts, thanks to the cobalt build that stands up to the heat of tough materials.

Drill America’s stepped point design combines a starter bit and a reamer in one tool, making it ideal for precise hole enlargement or multi-material work on a production bench. The set includes 29 incremental sizes from 1/16″ to 1/2″, a range suited more for exact metalwork than for general-purpose drilling in wood. According to research, Drill America’s own M42 cobalt bits were selected as best for hardened metal, while their carbide option offers greater durability at a higher price.

Its TiAlN coating withstands temperatures up to 1472°F, which drastically reduces heat and friction for a significantly longer tool life when drilling hard metals. That’s the key benefit for anyone regularly working with stainless steel or hardened cast iron. The triple-flute geometry on sizes 3/32″ and up provides approximately 40% improved chip ejection, promoting cooler operation and a superior hole finish.

You do trade some versatility for that focused performance. The set includes 21 essential sizes, covering over 90% of common tasks, but stops there. If you need a more exhaustive range, a larger set like the 29-piece IRWIN M35 could be a better fit. The manufacturer also notes the triple-flute design is recommended for standard depth of cut applications.

Its specifically crafted bullet point tip is sharp and self-centering, which minimizes wandering for precise drilling in metal. The titanium aluminum nitride coating increases surface hardness to 89HRC, providing heat resistance to help the bits stay sharp during heavy-duty use. This combination makes the set engineered for demanding scenarios where accuracy and durability are priorities.

The trade-off comes in the size selection. If your projects frequently require a complete ladder of sizes up to a half-inch, the more comprehensive IRWIN M35 set might be a better fit. However, for drilling pilot holes or finished holes where precise placement is non-negotiable, the Toolant’s engineered tip offers a distinct advantage that can save time and scrapped workpieces.

That 135-degree split point tip is the star here. It bites immediately, so you’re not chasing the bit across a steel plate. This makes the DEWALT set a reliable partner for general fabrication and repair work on mild and structural steel. The three-flat shank locks solidly into any drill, corded or cordless, which is a simple feature that saves immense frustration when pressure mounts. For a pro tackling a mix of materials or a serious DIYer drilling thick steel occasionally, this set covers the bases with well-thought-out engineering.

High-speed steel bits are intended for plastic, wood, and metal, but their heat resistance is lower than cobalt. In a test drilling stainless steel, high-speed steel bits from multiple brands were compared to cobalt and other types, using a consistent speed and force. For regular work with stainless or hardened steel, a cobalt set from another brand may offer longer life, but for general use in mild steel, wood, and plastic, this DEWALT set provides a straightforward toolkit.

If you’re regularly drilling holes from 9/16 inch up to a full inch in thick steel, the reduced shank on these bits is the key feature. That 1/2-inch shank lets you run large-diameter bits in any standard drill chuck, a major advantage over full-sized shanks that require a larger, specialized machine. The set is built for that specific heavy-duty task, with a split point that bites into hard metal without wandering and dual coatings that reduce friction. It’s a focused kit for anyone who needs to make big holes without investing in a giant industrial drill press.

This set contains eight large bits from 9/16 inch to 1 inch, so it’s designed for drilling bigger holes in tough materials rather than handling a wide range of tasks. You’ll need another set for smaller pilot holes or general-purpose drilling. All eight bits are stored together in a heavy-duty aluminum case, which keeps them organized and ready for transport to a job site.

Its split-point tip starts drilling immediately with less force, giving you control and preventing the bit from walking on the work surface. This IRWIN set provides a full range of sizes from 1/16- to 1/2-inch in 1/64-inch increments, so you’re likely to have the exact bit for the job. Made from 5% cobalt alloy steel, it resists heat and abrasion during extended drilling in tough materials. The included metal index case offers easy access and identification in a workshop.

The trade-off is material. High-speed steel will work-harden and lose its edge quicker than the cobalt or premium alloys in other picks like the BOSCH CO14B when you’re pushing through inches of thick plate. For extended, heavy-duty drilling in hardened steel, you’ll feel the difference in bit life. For general shop use, repairs, or projects where you’re not running the drill for hours on end, this set provides tremendous utility without a premium price tag.

The 5% cobalt content in these M35 bits is the key feature for anyone regularly tackling stainless or alloy steel. That alloy gives the steel the heat resistance to stay hard when the tip gets red-hot, which means you can push harder without immediately blunting the cutting edge. The 135° split point is a thoughtful touch, biting in fast and reducing the chance of the bit skating off your punch mark on a curved surface.

You do have to work with these bits correctly to get the advertised performance. The manufacturer explicitly advises using a cooling lubricant, which isn’t a suggestion but a requirement to prevent premature wear. Compared to a set like the Bosch CO14B, which has 14 pieces, the Yougfin offers more size options. For drilling through truly thick plate, the standard jobber length might become a limitation before you reach the other side, a trade-off for the set’s broad utility across common metalworking tasks.