Professional Tool Reviews for Pros
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. Cobalt Coated Hss Drill Bit
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.
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.
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.
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.
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
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
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
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.
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.
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.
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) 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.
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.
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.
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.
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.
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.
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.
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.
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!
Ever check out a “review” site and you can’t tell if they actually tested the tools or if they’re just “recommending” the Amazon top sellers? That’s not us. We won’t recommend anything unless we’d use it ourselves and we don’t care who the primary retailer is. It’s all about giving you a legitimate recommendation and our honest opinion of each product.
We’ve been in business since 2008 covering tools, writing reviews, and reporting on industry news in the construction, automotive, and lawn care industries. Our Pro reviewers work in the trades and have the skills and experience to know whether tools can perform well in the field.
Each year, we bring in and review more than 250 individual products. Our team will put our hands on hundreds of additional tools at media events and trade shows throughout the year.
We consult with innovators in the technology and design of tools to gain a broader grasp of where these products fit and how they work.
We work with more than two dozen professional contractors around the United States who review products for us on real job sites and consult with us on testing methods, categories, and weighting.
We’ll provide more than 500 pieces of new content this year absolutely free for our readers—including objective evaluations of individual tools and products.
The end result is information you can trust because of the editorial, scientific, and real-world professional experience we collectively utilize each and every time we pick up and test a tool.
When he's not playing with the latest power tool, Clint DeBoer enjoys life as a husband, father, and is an avid reader—especially the Bible. He loves Jesus, has a degree in recording engineering, and has been involved in multimedia and/or online publishing in one form or another since 1992.
Clint’s career has covered nearly the entire realm of audio and video production. After graduating at the top of his class with an Associates Degree in Recording Engineering, he began working for the famed Soundelux studios in 1994, one of the largest post-production companies specializing in audio for feature films & television. Working on a myriad of feature films, Clint honed his skills as a dialogue editor, foley editor, and sound designer. Years later, he moved into the expanding area of video editing, where he served as the company’s senior AVID video editor for three years.
Working for such clients as Universal Pictures, Hollywood Pictures, Paramount Home Entertainment, NASA, Universal Studios, Planet Hollywood, SEGA, NASCAR, and others, Clint DeBoer dealt extensively with client management as well as film & video editing, color correction, and digital video & MPEG compression. He also carries several THX certifications (Technician I and II, THX Video), and is ISF Level II Certified.
After founding the CD Media, Inc. publishing company in 1996, he went on to help start or grow several successful online publications, including Audioholics (as Editor-in-Chief for 12 years) and AV Gadgets. In 2008, Clint founded Pro Tool Reviews followed by the landscape and outdoor power equipment-focused OPE Reviews in 2017. He also heads up the Pro Tool Innovation Awards, an annual awards program honoring innovative tools and accessories across the trades.
Crediting God and his excellent staff for the success of what is now the largest power tool review publication in the industry, Clint DeBoer hopes to see continued growth for the company as it rapidly expands its reach. Pro Tool Reviews critically reviews hundreds of hand tools, power tools, and accessories each year to help inform users about the best and newest products in the industry. Reaching everyone from the construction industry professional and tradesman to the serious DIYer, Pro Tool Reviews helps tool consumers shop better, work smarter, and stay aware of what tools and products can help put them at the top of their game.
When asked if you would like to review “a tool belt or two” for Pro Tool Reviews, beware. After saying “Sure, […]
Having used and reviewed a LOT of the best portable toolboxes from just about every manufacturer, I’ve assembled my top […]
Laminate flooring is a popular choice for many homeowners. It’s a cost-effective flooring option available in many styles and colors. […]
While we’ve already addressed our thoughts about the best professional chainsaw and the best battery chainsaw we’re aware some people […]
As an Amazon Associate, we may earn income when you click on an Amazon link. Thanks for helping us do what we love.
See our Privacy Policy and Terms & Conditions.
Pro Tool Reviews is a successful online publication that has been providing tool reviews and industry news since 2008. In today’s world of Internet news and online content, we found that more and more professionals researched a large majority of their major power tool purchases online. That piqued our interest.
There’s one key thing to note about Pro Tool Reviews: We’re all about the professional tool user and tradesman!
Hss Drill Bit Straight Shank Copyright ©2008-2024 Pro Tool Reviews, LLC. All rights reserved.