10 Best Drill Bits To Drill Through Steel in 2026

The Bosch CO21 set is built for the serious task of drilling hard metals, with its cobalt construction and a no-skate tip that bites right in without wandering. It’s a reliable, well-rounded kit for the workshop, offering a logical spread of 21 sizes from 1/16-inch up to 1/2-inch. The three-flat shank on the larger bits is a thoughtful touch that really locks them into standard chucks. This set is a solid foundation for anyone who regularly tackles stainless steel, cast iron, or titanium and wants a trustworthy, versatile collection that covers most needs.

In a controlled test drilling stainless steel, the Bosch CO21 cobalt bits drilled 15 holes before wearing out, while another cobalt bit drilled 135 holes. This means for occasional projects on hard materials, the Bosch set is capable, but it may not be the longest-lasting choice for very intensive drilling tasks. The organized case helps keep the 21 assorted sizes readily accessible for general fabrication and repair work.

This 29-piece cobalt set covers a wide range of sizes, so you’re less likely to need a separate bit for common metal drilling jobs. Research round-ups mention Milwaukee’s Red Helix cobalt bits as a go-to choice for metal drilling with a cordless drill, citing excellent success. The set comes in a case measuring roughly ten inches long, which keeps all the bits together on a shelf or workbench.

That case size makes it a bench-top kit rather than a portable one. For a more compact option to carry to a job site, the Bosch CO14B set has a smaller footprint. However, in comparative drilling tests on stainless steel, the Milwaukee cobalt bits performed, while some non-cobalt bits from other brands failed to drill any holes.

An 8% cobalt M42 alloy gives these bits a serious edge when you’re staring down hardened steel or stainless. That surface-hardened tip and thick web-helix design mean they’ll bite in and stay put, resisting the heat that dulls lesser bits. This set is for the fabricator or mechanic who regularly encounters tough, abrasive materials and needs a bit that won’t soften under pressure.

Independent testing showed they drilled a fraction of the holes in stainless steel compared to the top performer, so for marathon production runs on thick stainless, your cost per hole might climb. If you need to blaze through dozens of holes quickly, look at the results for the Adiseal Ultimate. But for the weekend warrior tackling a hardened steel bracket or the pro who values Bosch’s consistent quality for intermittent tough jobs, these bits offer reliable penetration where standard high-speed steel would simply give up.

A 135-degree split point tip bites into hardened steel immediately, eliminating the frustrating dance a standard bit does before it starts cutting. This geometry, combined with a gold oxide finish that helps reduce heat compared to standard bits, contributes to a longer lifespan. The set suits a fabricator or serious DIYer who needs to punch clean holes through materials like steel plate or stainless. The stepped point acts like a built-in pilot, which can help create smoother holes when enlarging existing ones or starting new ones in multi-material drilling.

Compared to a general-purpose high-speed steel set, these Drill America bits are specialists for metal. They trade some versatility for performance in hardened materials like acrylic, steel, and brass. For most metal drilling tasks, this 29-piece collection delivers the easier starting and faster drilling that the brand claims, which can make a long project feel shorter.

The TiAlN coating’s ability to handle 1472°F makes these bits a standout for anyone regularly drilling hardened steel or alloys. That heat resistance directly translates to less wear and a longer lifespan when the work gets hot and heavy. These bits are designed for users who need reliable performance on tough materials like stainless steel and titanium, where friction and heat are the primary enemies of a drill bit. The comprehensive size range means it’s ready for most shop tasks right out of the box.

Its three-flute geometry is engineered for standard-depth drilling, producing rounder holes with a smoother finish while ejecting chips about 40% faster to keep the bit cooler. This design focuses on accuracy and surface quality in typical applications rather than deep, blind-hole work where chip evacuation can be challenging. Compared to other cobalt sets like the Bosch CO21, the Crosstar differentiates itself with a TiAlN coating rated for temperatures up to 1472°F, which can prolong life in demanding, high-heat scenarios.

The 135-degree split-point tip is the star here, biting into steel immediately so you don’t waste time chasing a wandering bit. It’s a reliable choice for the DIYer or occasional metalworker who needs a complete range of sizes from 1/16-inch up to 1/2-inch without a premium investment. The high-speed steel construction and corrosion-resistant finish deliver solid performance for general steel drilling where extreme heat resistance isn’t a daily demand.

The metal index case organizes the bits for easy access and identification. Compared to cobalt sets like the Bosch CO21 or Milwaukee Red Helix, this high-speed steel set is a different material choice. The product description states it is for extended drilling in tough materials, not specifically for hardened alloys like stainless steel or titanium.

The 1/4-inch hex shank is the key detail here. It locks these bits directly into your impact driver, turning that high-torque tool into a capable metal driller without an adapter. The titanium nitride coating and 135-degree split point are specifically engineered for that brutal, hammering action, biting into steel quickly and resisting wear far longer than a standard black oxide bit. This design suits the mechanic or framer who already lives with an impact driver in hand and needs to punch holes in steel strap, brackets, or sheet metal without switching tools.

You trade some versatility for that dedicated impact driver fit. The 14-piece assortment covers common sizes but can’t match the range of a 29-piece set like the Milwaukee Red Helix for a dedicated drill press setup. For drilling thick steel plate or a high volume of precise holes, a traditional cobalt bit in a drill with consistent RPM will still be the smoother choice. But when you need to drive a lag bolt into a steel beam or add a hole in a stud plate on-site, grabbing this Makita set means your impact driver is suddenly ready for that job, too.

These bits are barely over two inches long, so you can fit a drill into a cramped corner where a standard-length bit simply wouldn’t fit. That’s their entire reason for being. The M35 cobalt construction handles stainless steel and other tough metals, while the 1/4-inch hex shank lets you chuck them instantly into an impact driver or quick-change drill. They are ideal for a mechanic needing to drill out a broken bolt in a recessed engine block or a fabricator working inside a tight frame.

The trade-off for that compact profile is a very limited selection. With only five sizes from 3/32″ to 5/16″, you’ll need another set for most general metalworking tasks. For a comprehensive kit, the 21-piece Bosch CO21 provides far more size options. The NordWolf stubbies excel in their specific niche, but they’re a specialist tool, not your primary drill bit set. Keep them in your box for when space is the enemy, and reach for a jobber-length set for everything else.

The 135° split point is designed to automatically center and prevent walking, which means it starts accurately on curved or angled surfaces. This point also clears chips faster, reducing friction and heat for smoother drilling in tough metals. The M35 cobalt material provides better heat and wear resistance for a long tool life. These features make the GMTOOLS bits suitable for cutting stainless steel, steel, and cast iron.

The set includes 15 jobber-length bits ranging from 1/16″ to 3/8″. Compared to the 21-piece Bosch CO21 set, it offers fewer pieces and a smaller maximum diameter. The bits have round straight shanks, which are a universal fit, unlike the three-flat shank design listed for the Bosch CO21.

The tapered web design and 3-flats shank give these bits a serious backbone, making them exceptionally resistant to snapping under pressure. That core strength makes them a reliable pick for general steel drilling where you need a bit that won’t quit. They’re built for the user who wants a durable, well-rounded set from a trusted brand for a variety of materials, not just specialized for the hardest metals.

That’s a solid result, but it was outperformed by more specialized bits. If your work frequently involves stainless or hardened alloys, you’ll want to look at a dedicated cobalt option like the Bosch CO21 set. For drilling through standard steel plate or structural members, however, this set’s durability is hard to beat.