We already wrote our opinions on the best drill bits overall—covering wood, metal, concrete, and more. In this go-around, we wanted to identify the best drill bits for metal applications. That includes hardened steel, stainless steel, aluminum, and more. We even wanted to see which drill bits worked well for drilling out hardened bolts as you might find in an engine block. People also ask us about bits that handle drilling through rebar. These are the bits we turn to and should steer you in the right direction.
Our Top Picks
- Best Overall: Drill America D/A29J-CO-PC 29-pc Cobalt Set – Buy on Amazon
Jump to this Bit ↓ - Best Set: Irwin 29-piece Cobalt M-42 Metal Index Drill Bit Set – Buy at Amazon
Jump to this Bit ↓ - Best for Soft Steel: Milwaukee Red Helix Cobalt Drill Bits – Buy at Acme Tools
Jump to this Bit ↓ - Best for Rebar: Diablo Rebar Demon Bits – Buy at Acme Tools
Jump to this Bit ↓ - Best Metal Hole Saws: Milwaukee Hole Dozer Carbide Hole Saws – Buy at Acme Tools
Jump to this Bit ↓ - Best Step Bits for Metal: Irwin Unibit Cobalt Step Bits – Buy at Amazon
Jump to this Bit ↓ - Best for the Money: DeWalt DWA1240 14-pc Cobalt Drill Bit Set – Buy on Amazon
Jump to this Bit ↓
Also in this Article
- Best Selling Drill Bits for Metal
- More Drill Bit Recommendations
- Understanding Drill Bit Materials
- How Cobalt Blends Help When Drilling Steel
- Why You Can Trust Pro Tool Reviews
Best Drill Bits Overall – Best for Hardened and Stainless Steel
Drill America D/A29J-CO-PC 29-pc Cobalt Set
Drill America makes M42 cobalt bits that held up really well in drilling through anything we threw at them. After testing with a multitude of materials, we selected their jobber bits as our best drill bits for hardened steel.
The bits feature the expected 135° split point, which gives you a nice, steady, and productive drilling speed. The jobber length bits work perfectly in cordless drills for onsite drilling. They come manufactured to the National Aerospace Standard 907. Because of how hard they are, you can drill up to 30% faster than you can with conventional M2 high-speed steel bits. Drill America also doesn’t grind down the shafts on its larger bits—so you get more rigidity, but you also need a 1/2-inch chuck to drive them.
Use these bits when drilling tough, high-tensile strength materials like stainless steel—or even titanium. We opted for the D/A29J-CO-PC kit. It includes 29 bits in a shatterproof case. The round case makes it simple to remove the exact bit you need.
Pick up the Jobber Length Drill America D/A29J-CO-PC kit for just $120.
Best Metal Drill Bit Set
Irwin 29-piece Cobalt M-42 Metal Index Drill Bit Set
If you plan on drilling hardened metal or steels, we love the Irwin 29-piece M-42 Cobalt bit kit as our best metal drill bit set. Honestly, it’s not the fastest drilling bit that gets it our nod. It has to do with the use of M42 high-speed steel and its excellent case.
Many less expensive cobalt drill bits use M35 steel which has a 5% cobalt blend. M42 steel uses an 8% cobalt blend. This gives it a greater hardness. It also lets you drill at higher speeds than the M35. Irwin sells an M35 cobalt set as well if you don’t plan to drill hardened steel.
Which brings us to the case. If you do a lot of drilling—the case your bits come in matters. Accessing bits can be frustrating (we’re talking to you Milwaukee!) or hugely successful—like with this Irwin three-tier swing case. We love the easy-access bits, and you can easily tell the sizes from the front of each bit. Overall, this $179 kit gives you the best drill bits for metal applications of all kinds.
Best Drill Bits for Steel (Non-Hardened Carbon Steels)
Milwaukee Red Helix Cobalt Drill Bits
Listed in our best drill bits article, Milwaukee Red Helix cobalt bits use a variable flute design that clears away debris quickly. How quickly? About 30% faster than most other 135° split-tip bits we tested against. Their unique design not only helps them drill efficiently, but it also aids in cooling. The trade-off is that these bits thin out more towards the tip. Milwaukee countered this by making them a bit shorter than some others we’ve seen. However, they also extended the flutes lower towards the shaft. The result is a more compact bit with a similar drilling depth.
The 135° split point tip helps when starting your hole and larger sizes feature a Chip Breaker—a groove at the midpoint of the cutting edge that further reduces heat buildup. We love how quickly these bits drill and also how well they remove steel in tight, efficient spirals. The combination of the unique cutting head and the flute design landed these as our best drill bits for steel—particularly carbon steel.
Lacking a 1/4″ hex, use these in your drill or drill press when you need them for thicker, harder metals.
Thanks to the cobalt steel blend, plan on sharpening these when the tips grow dull from use. The value of this kit makes these the best drill bits for steel.
You can find the 15-piece kit for $38 or the 29-piece kit for $150.
Best Drill Bit for Rebar
Diablo Rebar Demon Bits
Sometimes you need to drill through steel…but that steel is buried in concrete. For those applications, you need something like the Diablo Rebar Demon SDS-Max and SDS-Plus bits. We like the design better than Bosch Rebar Cutters because you use the same bit to drill the hole and penetrate the rebar. With Bosch, you drill using rotary hammer mode, switch to the Rebar Cutter in rotary-only mode, and then return to your original bit to finish the hole.
These bits drill quickly through concrete then continue right through rebar. You really can’t find much else on the market that competes at this point, so it’s an easy recommendation for productivity. We believe in charging your accessories to the job—so if a simple bit can save you time and money, it’s a huge win in our book. Pricing goes anywhere from $6–$206.
Best Hole Saws for Metal Drilling
Milwaukee Hole Dozer Carbide Hole Saws
The Milwaukee Hole Dozer with Carbide Teeth really wins for metal drilling. It can tackle stainless steel and certainly anything softer or milder than that. These are the best hole saws for metal drilling that electricians, HVAC, and/or MRO Pros can use.
Because they work effectively in both metal and wood, any Pro looking for a general-purpose set of hole saws should quickly fall in love with their productivity. It vastly outperforms bi-metal blades and tackles those materials carbide wood hole saws can’t (or shouldn’t) touch. You can buy kits from $105-$190
Best Step Bits for Metal
Irwin Unibit Cobalt Step Bits
Our team grabs Irwin Unibit Cobalt Step Bits for any quick thin metal drilling applications. The cobalt blend gives these bits a much longer life. Since step bits are both expensive and extremely difficult to sharpen, we like them to last as long as possible.
Irwin gives these bits a Speedpoint tip. It helps get the hole started quickly and reduces wandering. We also have to admit these became our best step bits for metal in part because Irwin laser-etched the measurements right on the inside of the flute. They don’t wear off quickly like other bits we’ve used.
Pick up a 3-piece kit for $69
Best Metal Drill Bits for the Money
DeWalt DWA1240 14-pc Cobalt Drill Bit Set
When it comes to the best value pick, we wanted a set of bits for basic metal drilling. The DeWalt DWA1240 14-pc Cobalt Drill Bit Set employs a nice cobalt blend that gives these bits more capability over titanium-coated bits. You get a nice set of 14 bits ranging from 1/16-inch to the commonly-used 3/8-inch.
To make it even better, you get a nice kit with clearly labeled bit sizes. The largest bits also feature the DeWalt Pilot Point which presents walking at the start of drilling.
Pick up the kit for $29
Best-Selling Drill Bits for Metal
Looking at the best-selling metal drill bits on various trusted retailers helps when shopping. You often run into the best value, and we find the less expensive kits often find themselves at the top of these lists. We dropped links to what was at the front at the time we were writing, but they change often, so be sure to click the buttons to see what’s hot right now.
Amazon
- DeWalt DW1361 Titanium Nitride Coated Drill 21pc Bit Set – $25
- Bosch CO14B 14pc Cobalt M42 Metal Drill Bit – $34
- Cobalt SAE 13pc Drill Bit Set – $16
Acme Tools
- Milwaukee Shockwave Impact Duty Red Helix Titanium Drill 23pc Bit Set – $35
- Milwaukee RED HELIX Cobalt Drill 29pc Bit Set – $150
- Irwin 29pc Cobalt Industrial Drill Bit Set – $130
Lowe’s
- Kobalt 21pc Titanium Jobber Length Twist Drill Bit Set – $20
- Spyder Stinger Mach-Blue 10pc High-speed Steel Jobber Drill Bit Set – $30
- DeWalt 21pc Titanium Nitride Coated HSS Jobber Drill Bit Set – $32
Home Depot
- Milwaukee Shockwave Impact Duty Red Helix Titanium Drill 23pc Bit Set – $35
- Ryobi 22pc Titanium Twist Drill Bit Kit – $15
- Milwaukee 23pc Cobalt Red Helix Twist Drill Bit Set for Drill Drivers – $65
More Metal Drill Bit Recommendations from Brands We Trust
Best Ryobi Metal Drill Bits
Ryobi 22pc Titanium Twist Drill Bit Kit
Homeowners should get a lot of use from this set—and the hex shanks work well with impact drivers.
Price: $15
Best Bosch Metal Drill Bits
Bosch CO21B 21pc Cobalt M42 Metal Drill Bit
For Pros looking for a reliable kit that should last a long time while providing plenty of options, this 21-piece kit delivers.
Price: $59.22
What are the Best Drill Bits for Metal Made of?
You can find many types of drill bits made with an equally diverse amount of coatings and compositions. When it comes to the best drill bits for metal, however, only a few materials hold up well over time.
High-Speed Steel (HSS)
High-Speed Steel (HSS) Drill Bits present an upgrade over older carbon steel bits. Able to hold up better to excessive heat and wear, they make up a majority of drill bits sold on the mass market. You can use these bits for just about anything—so they serve as a jack-of-all-trades for both wood and metal applications. HSS dulls very quickly when used on more abrasive material.
Titanium Coated Drill Bits (TiN or TiCN)
Drill bits made with a Titanium nitride coating resist corrosion and friction. It beats black oxide because it increases surface hardness and does a better job reducing heat while drilling through metal. For metal drilling, we recommend these as the bare minimum.
With titanium nitride, you have to remember it only coats the bit. As the coating wears off the cutting edges, you pretty much have to replace them. Don’t use these bits for drilling hardened steel or stainless—not if you want them to last.
M35 vs M42 Cobalt (Steel Blend)
Our best Cobalt drill bits for metal drilling are made from an alloy of 8% cobalt (M42). You can also find these bits with a 5% cobalt blend (M35). Since the cobalt is blended into the steel, it doesn’t wear away like a titanium or black oxide coating. That also means you can sharpen them with something like the Drill Doctor 750X drill bit sharpener before having to replace them. This helps save money when you buy these more expensive bit sets. Cobalt bits are our go-to for drilling through metal—particularly hardened steel and stainless steel.
Mach-Blue or Titanium Nitride and Aluminum (TiAlN) Coated Bits
Spyder uses a proprietary Mach-Blue plating on its drill bits. Likely a form of Titanium Nitride and Aluminum (TiAlN) coating, it helps retain sharp cutting edges and reduce heat build-up. This should deliver faster cuts and help extend the life of the bit.
Possibly even more important, underneath blue nano coatings you typically find heat-treated M-Series tool steel.
Avoid These Types of Bits for Consistently Drilling Steel
If you want to drill steel reliably, avoid anything made with low-carbon steel. Even generic high-carbon steel tends to work well for a little while—but quickly dulls and requires sharpening.
Black oxide drill bits also tend to dull quickly. We also recommend avoiding inexpensive steel drill bits that lack any sort of coating. While those bits may do well in softer steel, they can quickly dull and require frequent sharpening to continue to perform. In most cases, you get what you pay for.
How Cobalt Blends Help When Drilling Steel
Clearly, the best drill bits for hardened metal or steel come with a cobalt blend. These cobalt drill bits use an alloy including 5%–8% cobalt. This cobalt makes up part of the steel blend, so the hardness of the bit doesn’t wear off with a coating (like titanium bits). It runs throughout the entire bit.
You can also sharpen these bits—another huge advantage. That matters once you realize cobalt drill bits cost significantly more than other types of twist drill bits. Unlike black oxide or titanium bits, you want to reserve these bits for when you need them.
When drilling a hole with a cobalt bit, add a drop of oil on the metal to keep the cutting edge cooler as it cuts. You also want to consider placing some wood underneath the steel if possible. This lets you cut cleanly through the material and not strike a surface below which might dull the cutting edge.
Drilling Into Hardened Steel
When we talk about drilling in hardened steel, we mean medium or high carbon steels typically made using a heat-treatment and tempering process. Hardened steels are durable and can be wear-resistant, corrosion-resistant, and abrasion-resistant. Much of the steel materials that we see used in mechanical engineering, energy generation, and transportation are basically hardened steel. The best drill bits for metal could be designed for these hardened steel applications or they might be optimized for speed in softer carbon steels.
Drilling Into Stainless Steel
Stainless steels are steel alloys consisting of at least 10.5% chromium and there are different grades. As a low-carbon steel, stainless steel has a natural hardness that comes without traditional hardening. Because of rust and stain resistance, good luster, and low maintenance, it has many commercial uses including cookware, cutlery, home appliances, construction fasteners, and surgical instruments.
stainless can actually harden up as it heats—so drilling slowly often helps you get through the material more efficiently. Use cutting oil or similar lubricant when drilling into stainless and apply enough pressure to see a steady removal of material. Even the best drill bits for stainless steel heat up over time, so be prepared to monitor heat buildup.
However, whatever differences there are between the outer look or chemical composition, both hardened steel and stainless steel are quite difficult to drill into. Using a drill press is often the best way to get quality results.
Disagree With Our Choices?
That’s okay! We know personal preferences take a front seat in determining the best drill bit, and every Pro is different. Do Pro Tool Nation a favor and tell us what your top pick is and why you love it. Feel free to put it in the comments below or on Facebook, Instagram, and Twitter!
Why You Can Trust Pro Tool Reviews
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