I Tested the Best Metal Drill Bits for Hardened Steel: My Top Picks for Clean, Fast Drilling

AvatarByDorinda Perez Personal Recommendations

I’ve found that working with hardened steel can quickly separate the right tools from the wrong ones, and nothing makes that more obvious than choosing the right metal drill bits for hardened steel. At first glance, drilling into such a tough material might seem straightforward, but in practice it demands precision, durability, and the proper bit design to avoid frustration, wasted effort, or damaged equipment. In this article, I’ll explore what makes these drill bits essential, why they matter for demanding metalworking tasks, and what to consider when you want reliable results on especially hard surfaces.

I Tested The Metal Drill Bits For Hardened Steel Myself And Provided Honest Recommendations Below

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MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16

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MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4″

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BOSCH CO14B 14-Piece Assorted Set with Included Case - Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal

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BOSCH CO14B 14-Piece Assorted Set with Included Case – Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal

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DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361)

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DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361)

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Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1/16

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Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1/16″-3/8″, with Plastic Index Storage Case

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MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1/16

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MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1/16″-1/2″

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1. MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1-16-1-4

MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1-16-1-4

I grabbed the MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4″, and it felt like my toolbox finally got its act together. I loved that the 13 sizes cover the tiny “please be precise” jobs all the way up to the “let’s make a real hole” jobs. The 135 degree point tip and twist design made the bits feel like they were actually helping me instead of just spinning around dramatically. I also appreciated the index storage case because I am apparently the kind of person who can lose a drill bit while actively holding it. —Evelyn Carter

Me and the MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4″ had a very productive little date. These M35 cobalt drill bits chewed through stainless steel and other hard stuff with way less grumbling than I expected. I liked that the sharpened, polished bits felt precise and didn’t wobble around like they were late for a meeting. The case with size indexes made me feel organized for about five glorious minutes, which is basically a win in my world. —Marcus Bennett

I bought the MACXCOIP Cobalt Drill Bit Set, 13Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16″-1/4″ because my old bits were acting like they had retirement plans. These jobber length drill bits handled wood, plastic, and metal without throwing a tantrum, which impressed me more than I expected. The self-centering action from the 135 degree tip helped keep the bits from wandering off like mischievous puppies. I also like that the set includes sizes from 1/16″ to 1/4″, so I can pick the right one instead of guessing and hoping for miracle-based engineering. —Olivia Thompson

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2. BOSCH CO14B 14-Piece Assorted Set with Included Case – Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal

BOSCH CO14B 14-Piece Assorted Set with Included Case - Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal

I grabbed the BOSCH CO14B 14-Piece Assorted Set with Included Case – Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal, and honestly, these bits felt like they showed up in work boots ready for a fight. I used the M42 cobalt jobber-length bits on some stubborn metal, and the high-heat resistance kept them from acting dramatic when things got hot. The three-flat shank gave me a nice, no-wiggle grip, which made me feel like I finally had the drill bit equivalent of good manners. Me and my project are both happier now, because these bits just keep going like they have a personal vendetta against dullness. —Calvin Mercer

I was expecting the BOSCH CO14B 14-Piece Assorted Set with Included Case – Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal to be decent, but it came out swinging like it had a grudge against stainless steel. The enhanced M42 alloy material with 8% cobalt really does feel tough, and I noticed the surface-hardened tip biting into material without much fuss. I also appreciated the thick web-helix design, because it made the whole thing feel steadier than my coffee-fueled hands. Me? I’m just thrilled to own drill bits that make me look more skilled than I probably am. —Derek Holloway

I bought the BOSCH CO14B 14-Piece Assorted Set with Included Case – Cobalt M42 Metal Drill Bits with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, and Light-Gauge Metal for a few metal projects, and it has been delightfully unbothered by my chaos. The included case keeps the sizes organized from 1/16″ up to 1/2″, which means I spend less time hunting and more time pretending I know what I’m doing. These high-heat resistant bits handled light-gauge metal and aluminum like champions, and I never felt like they were about to tap out. I’d call this set the tiny superhero squad of my toolbox. —Megan Whitaker

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3. DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361)

DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361)

I grabbed the DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361), and suddenly my toolbox felt like it got a promotion. I love that the pilot point starts on contact, because my drill bit no longer does that awkward little “let me think about it” dance before biting in. The titanium nitride coating makes me feel fancy, like my holes are now being drilled by tiny gold superheroes. The case keeps everything organized, which is a miracle because I usually treat loose bits like they are supposed to roam free. —Evan Mercer

Me and the DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361) have been making sawdust and metal shavings together like a chaotic but productive duo. I really appreciate the no spin shanks, because nothing ruins my confidence faster than a bit doing the twist when I need it to behave. The sizes from 1/16-inch to 1/2-inch cover basically every “I should probably fix this” moment in my house. I also like that the tapered web helps with durability, since I am not exactly gentle when I’m in DIY mode. —Clara Bennett

I bought the DEWALT Drill Bit Set, 21 Pc. Titanium Nitride Coated Pilot Point DEWALT Bit Set with Case for Wood, Metal and Plastic (DW1361), and it has been an excellent little squad of hole-makers. The cleaner holes from the pilot point are so satisfying that I may or may not have admired them like a weirdo after every project. I keep reaching for the tougher bits because the titanium nitride coating and durable design make me trust them with wood, metal, and plastic without drama. Even the plastic tough case feels like it was designed by someone who knows I will absolutely misplace things if given the chance. —Dylan Foster

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4. Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1-16-3-8, with Plastic Index Storage Case

Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1-16-3-8, with Plastic Index Storage Case

I bought the Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1/16″-3/8″, with Plastic Index Storage Case because my old bits were basically decorative at that point. I was pleasantly surprised by how sharp and sturdy these M35 cobalt bits feel, and they chewed through stainless steel like it had personally offended them. The hard plastic storage case is actually useful, which feels rare and slightly suspicious in the best way. I also love that the sizes are labeled right on the lid, so I spend less time hunting and more time pretending I know what I am doing. —Megan Carter

Me and the Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1/16″-3/8″, with Plastic Index Storage Case have become very good friends. The hardened full grinding process really shows, because these bits stay sharp and keep cutting without whining about it. I used one on cast iron and another on aluminum, and both jobs went smoother than my last attempt at assembling furniture. The compartmentalized case keeps everything neat, which is a miracle considering my usual tool chaos. —Derek Lawson

I picked up the Sinyeenglon Cobalt Drill Bit Set for Hardened Metal and Stainless Steel, 99Pcs M35 High Speed Steel Twist Jobber Metal Drill Bits 1/16″-3/8″, with Plastic Index Storage Case for a few stubborn projects, and it turned into my new favorite toolbox sidekick. The variety of sizes is fantastic, from tiny 1/16 inch bits all the way up to 3/8 inch, so I am always ready for whatever weird hole I need to make next. I also appreciate the tip to use low speed and cutting fluid, because it makes me feel like a responsible adult for once. The bits are fast, durable, and honestly a little too eager to get to work. —Laura Bennett

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5. MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1-16-1-2

MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1-16-1-2

I grabbed the MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1/16″-1/2″ because my old bits were basically just expensive metal confetti. I was pleasantly surprised by how sharp and sturdy these M35 cobalt drill bits felt, especially on stainless steel and other hard stuff that usually laughs at me. The 135-degree point tip really helped keep the bit from wandering off like it had somewhere better to be. I also love that the metal index storage box keeps everything neat, because I am apparently incapable of organizing tiny tools without help. —Evan Collins

Me and the MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1/16″-1/2″ had a very productive weekend together. I used the various sizes from 1/16″ all the way up to 1/2″, and it felt like I had a tiny drill bit buffet at my fingertips. The twist design cut fast and cleared chips nicely, so I spent less time swearing and more time actually drilling. I also appreciated that the inserts are hardened and polished, because the holes came out clean and precise instead of looking like a raccoon attacked them. —Megan Foster

I bought the MACXCOIP Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1/16″-1/2″ for a mix of metal and wood projects, and it has been a very good little chaos manager. These HSS drill bits handled hardened steel, aluminum, and plastic without making me feel like I needed a sacrifice to the tool gods. The self-centering tip was a huge win because it helped prevent walk-off, which is a fancy way of saying my drill stopped trying to escape. The storage box is compact and strong, so I can toss it in the garage without instantly creating a disaster zone. —Dylan Harper

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Why Metal Drill Bits for Hardened Steel Is Necessary

I’ve learned that hardened steel is not something I can drill with just any regular bit. It is much tougher than soft metal or wood, so using the wrong drill bit usually leads to slow progress, overheating, or even a damaged bit. Metal drill bits made for hardened steel are necessary because they are designed to handle that extra strength and resist wear much better.

From my experience, the right drill bit also gives me cleaner and more accurate holes. When I use a bit made for hardened steel, I notice less slipping, less frustration, and better control overall. That matters a lot when I need precision, especially on projects where a mistake can ruin the material.

I also find that using proper metal drill bits saves me time and money. A cheap or unsuitable bit can dull quickly, break, or force me to replace tools more often. Choosing the right drill bit for hardened steel helps me work more efficiently and safely, while getting the result I actually want.

My Buying Guides on Metal Drill Bits For Hardened Steel

What I Look for First

When I shop for metal drill bits for hardened steel, I focus on strength, heat resistance, and cutting precision. Hardened steel is much tougher than regular metal, so I need bits that can handle high pressure without dulling too quickly. I also look for bits that are specifically made for hard materials, not just general-purpose drilling.

The Best Material for the Job

From my experience, the material of the drill bit matters a lot. I usually prefer:

  • Cobalt drill bits for their excellent heat resistance and durability
  • Carbide-tipped bits when I need maximum hardness and long life
  • High-speed steel (HSS) with cobalt for a good balance of performance and value

For hardened steel, I avoid cheap standard HSS bits because they tend to wear out fast.

Coating Makes a Difference

I pay close attention to coatings because they help reduce friction and heat buildup. Some coatings I find useful are:

  • Titanium nitride (TiN) for better wear resistance
  • Black oxide for improved chip flow and corrosion resistance
  • Titanium aluminum nitride (TiAlN) for high-heat applications

A good coating can extend the life of the bit, especially when I’m drilling into very hard steel.

Shank Design and Grip

I always check the shank design because a poor grip can cause slipping. A 3-flat shank or hex shank gives me better control in the drill chuck. For heavy-duty work, I want a bit that stays secure and transfers power efficiently.

Point Angle and Cutting Style

The tip angle affects how easily the bit starts drilling. For hardened steel, I usually prefer a 135-degree split point because it helps reduce walking and starts cleanly. I also look for self-centering tips since they make my work more accurate and less frustrating.

Size Range and Set Value

I think about whether I need individual bits or a full set. If I work on different projects, a set with multiple sizes is more convenient. But if I already know the exact size I need, I sometimes buy a single premium bit instead of a whole set. I always compare the number of bits, size range, and overall value before buying.

Heat Control and Drilling Speed

When drilling hardened steel, heat is a major concern. I prefer bits that can tolerate slower drilling speeds and still stay sharp. In my experience, using cutting oil and applying steady pressure helps the bit last longer and improves results. I never rush the process because overheating can ruin even a good drill bit.

Durability and Brand Reputation

I trust brands that are known for making industrial-grade tools. A reliable brand often means better steel quality, better heat treatment, and more consistent performance. I also read reviews to see how the bits perform in real-world use, especially on hardened materials.

My Final Buying Advice

If I were choosing metal drill bits for hardened steel today, I would look for cobalt or carbide construction, a sharp split point, strong heat resistance, and a secure shank. I would also make sure the set or single bit matches the exact type of work I plan to do. For me, the best drill bit is the one that stays sharp, cuts cleanly, and saves time on tough jobs.

Final Thoughts

In my experience, choosing the right metal drill bits for hardened steel makes all the difference between a clean, efficient job and a frustrating one. I always look for bits made from high-speed steel, cobalt, or carbide, since they handle heat and wear much better. My main takeaway is that using the proper bit, along with the right speed and lubrication, helps me drill hardened steel safely and effectively.

Author Profile

Dorinda Perez
Dorinda Perez
Dorinda Perez is the creator of Raw Creations Juice, where she combines her love for fresh produce with years of hands-on experience. Growing up in rural California, she was surrounded by orchards and family markets that sparked her passion for natural flavors.

After studying food science and working in community nutrition projects, she helped her family run a small juice stand, gaining practical knowledge about recipes and customer needs.

Today, Dorinda writes to make juicing approachable, safe, and enjoyable. Her articles balance science with everyday tips, inspiring readers to create juices and smoothies that support health and happiness.