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In a hurry? While I recommend reading the whole article to find the cobalt drill bit set that best suits your needs, I have to mention here that this one from Irwin is my favorite. It contains 29 bits covering all the sizes you might need for regular projects and offers a good balance between performance and cost.
Irwin M35 Cobalt Steel Drill Bit Set
A set of 29 cobalt drill bits offering good cost-performance.
While in most cases, regular high-speed steel drill bits will do the job just fine, there are some situations in which more strength is required. In those cases – like when drilling through tough pieces of metal – cobalt drill bits are a much better choice.
In this article, I will take a look at what I think are the seven best cobalt drill bit sets. Before jumping into the individual reviews of the picks, here’s a quick list of the top three:
- Top Pick: Irwin M35 Cobalt Steel Drill Bit Set
- Runner-Up: Bosch CO21B 21-Piece Set
- Budget-Friendly Option: DeWalt 14-Piece Cobalt Drill Bit Set
Top Pick: Irwin M35 Cobalt Steel Drill Bit Set
This Irwin drill bit set contains 29 bits made from industrial grade cobalt steel. The bits range in sizes from 1/16- to 1/2-inch in 1/64-inch increments and have 135-degree split-point tips. The tips help increase efficiency by allowing to drill with less force and eliminating “walking” across the work surface. The 8% cobalt alloy is heat- and abrasion-resistant.
The toughened bits are ideal for drilling tough metal including heavy-duty abrasive alloy metal or hardened steel. The bits come packaged in a metal index case that makes it easy to access and identify the individual bits.
Things I Like About This Product: The kit has a good range of sizes, so drilling holes of the right size will not be a problem. The quality is excellent and the bits do what the manufacturer claims, which is drilling through hardened metal with no troubles.
Things to Keep in Mind Before Buying This Product: These bits are very sharp so you may need a hex or flatted shank when drilling metal or they can bite and dig into the metal surface. One issue with the case is that it doesn’t close completely tight, and the printed bit size on the case is not easy to read.
Runner-Up: Bosch CO21B 21-Piece Set
The Bosch 21-piece M42 drill bit set includes, as its name suggests, bits made from M42 Cobalt alloy that contains 8% cobalt. These bits are highly durable and heat resistant. Their hardened surface is ideal for drilling stainless steel, cast iron, titanium, light-gauge metal, and aluminum.
The bits’ no-skate tip is fast and accurate, and won’t walk on the material’s surface. The bits that are 1/8-inch or larger feature a split point while bits that are 3/16-inch or larger feature a three-flat shank for a better bit grip.
Things I Like About This Product: These bits are of the usual Bosch quality with robust design and long-lasting durability. Their no-slip shanks let you chuck right up to them without worrying about breakage. As long as the bit is rotated slowly, cutting oil is used, and the angle is right, these bits will cut through even the hardest steel smoothly.
Things to Keep in Mind Before Buying This Product: The bit sizes stamped on the bit are hard to read.
Budget-Friendly Option: DeWalt 14-Piece Cobalt Drill Bit Set
The DeWalt DWA1240 cobalt drill bit set is designed for drilling in stainless steel and other hard metals. The bits have pilot points and slit tip designs to prevent bit walking and to ensure maximum speed, user control, and extended life.
Things I Like About This Product: These drill bits are sharp, durable, and will survive almost anything as long as you have a clean, straight drilling technique, and use oil when drilling into metal. The case is quite useful because it folds and locks with a slide, a feature that’s standard on DeWalt drill bit sets.
Things to Keep in Mind Before Buying This Product: Some users have complained of slow drilling on hardened stainless steel or hard metal. Many issues can be resolved by using a slower speed, using cutting oil, and letting the drill do the work rather than forcing the bit in.
Premium Option: MaxTool 29-Piece M42 Cobalt Drill Bit Set
MaxTool’s M42 cobalt drill set contains 29 quality bits made from 8% cobalt high-speed steel in sizes ranging from 1/16-inch to 1/2-inch in 1/64-inch increments. The precision-ground bits are designed for smooth, accurate, and durable performance.
The golden coating is corrosion resistant and increases the hardness of the drill bits.
In addition, the 135-degree split point prevents walking across the surface and allows the bit to penetrate hard material without a pilot hole. The drill bits can be used for cutting metal, plastic, wood, and other materials.
Things I Like About This Product: These drill bits can cut through hard metals with ease, and make quick work of boring or drilling tasks that would take other bits a long time. The bits don’t dull even after several dozen holes, and they perform well if the drill RPMs are kept low and cutting oil is used.
Things to Keep in Mind Before Buying This Product: Some reviews state that the bits got dull after a bit of use, but this can usually be avoided by using cutting oil along with low RPMs.
The Alternatives: Products Also Worth Considering
While I recommend getting one of the four sets mentioned above, if you did not find one you like among those, you might also want to consider the three products below.
Drill America 29-Piece M35 Cobalt Drill Bit Set
Drill America’s 29 piece set of jobber length drill bits includes sizes 1/16-inch to 1/2-inch in 1/64-inch increments. Each of the bits has a gold oxide finish that provides wear resistance and extends the tool life compared to regular high-speed steel drill bits. That’s especially the case when drilling hard materials.
The bits have a self-centering 135-degree split point that penetrates hard material without a pilot hole and produces small chips to reduce clogging. Compared to a conventional 118-degree tip, these drills won’t go “walking” on you.
Most drill chucks can accommodate the bits’ round shank. The set comes in a plastic index case with labeled compartments for identification and organization. The drill bits conform to American National Standards Institute (ANSI) standards.
Things I Like About This Product: The drill bits are spirally organized in a small canister, making them easy to locate and replace in their labeled slot when broken. They are sharp and true to size. Even the smallest sizes have split points which is not the case for many sets out there. Every bit is ground well and the gold oxide finish provides lubrication to the bit while drilling. The drill index case is sturdy and stores the bits well.
Things to Keep in Mind Before Buying This Product: As long as the right angle, speed and lubricant are used, the result will be clean, smooth cuts every time.
Drill Hog 21-Piece Cobalt Drill Bit Set
Drill Hog’s 21-piece drill bit set is a good choice for people who need to drill through hard metals, especially since the M42 cobalt steel is extra tough.
The 135-Degree split point prevents “walking” and the flat sides on shank prevent “spin” in the chuck. Drill Hog backs its bits with a lifetime warranty, so you can register your set on their website and get free replacement bits if yours break.
Things I Like About This Product: The drill bits do a great job drilling holes in hard metal and are best used at low RPMs and low power, along with cutting oil. I also love the lifetime warranty from Drill Hog, under which any damaged or broken drill bit can be replaced free of charge.
Things to Keep in Mind Before Buying This Product: Some reviews mention that the coating on the bits was contaminated with particles of some sort, leaving a rough surface. That said, it didn’t seem to make much difference in usage.
Milwaukee 29-Piece Cobalt Helix Drill Bit Set
This Milwaukee drill bit set contains 29 brad point bits that are specifically made for drilling in extremely hard and thick metals like cast iron and stainless steel. The bits have a center point design that keeps the drill bit from skating as it enters the wood or other material resulting in perfectly smooth, splinter-free holes.
The drill bits come inside a durable case with an index.
Each bit is made from 5% cobalt infused carbon steel and is very tough. Combined with the red helix bit design and non-walking 135-degree tip, these are some of the toughest bits available.
Things I Like About This Product: The plastic case is well designed and of durable construction. The bits can be easily identified and replaced using the index.
Things to Keep in Mind Before Buying This Product: While they’ll drill almost anything, it is recommended to use them for hard metals rather than wood.
The Methodology: What I Considered When Picking the Products Featured Above
When going through the dozens of cobalt drill bit sets available on the market, I looked – among other things – at the following criteria to pick the list of the best ones for you.
Price:There’s no doubt that price is a major consideration no matter what the product you are buying is. However, I took it into account relative to how the products performed on the other criteria. As such, the only category where the price of the bits was the deciding factor was the “best budget-friendly option” where the DeWalt DWA1240 cobalt drill bit setwas the winner.
Quality: The more important criteria to consider was the quality of the product. The three main ways to assess a product’s quality are looking at the reputation of the brand that makes it, looking at the type and percentage of cobalt contained within the bit, and going thoroughly through positive, negative, and neutral reviews. Overall, all of the products I featured in the list are of decent enough quality in relation to their price and intended usage. However, if I had to choose one that wins on this front, it would be the “premium option,” MaxTool’s M42 cobalt drill set.
Versatility: With tools and accessories that come in many sizes – like drill bits – it is not only important how good of a quality each bit is, but also how many bits each set contains. That’s especially true if you are getting a set “just to have one” rather than for some specific purpose where you know which size you will need. On that front, it was a tie between a few products in the list, including the Irwin drill bit set and the Milwaukee drill bit set, each of which includes 29 different bits.
The FAQs: Things You Need to Know About Cobalt Drill Bits
If you are unsure whether cobalt drill bits are what you actually need for your job – or if there is a question you have about them – chances are you will find your answer below.
What are cobalt drill bits made from?
While their name suggests they are completely made from cobalt, that is not the case. Instead, cobalt drill bits are generally made from high-speed steel which contains a certain percentage, usually 5% to 8% of cobalt.
You can read more about the topic in my article comparing black oxide, cobalt, and titanium drill bits.
Can I use cobalt drill bits with wood?
Yes, you can, but it will be an overkill. I recommend using standard high-speed steel bits for that. Instead, reserve the expensive cobalt drill bits for drilling into tough materials like metal.
Can I sharpen cobalt drill bits?
Because they are made of quality materials, cobalt drill bits tend to stay sharper longer than other types of bits. That is, however, assuming the same usage. With cobalt drill bits often being used in much tougher conditions, you will need to sharpen yours every now and then.
You can do so using a bench grinder among other ways.
Summary
Cobalt drill bits are not for everyone, after all, they are just one of the many types of drill bits. They are expensive compared to standard steel bits and, for most purposes, they are overkill. Using them to drill into wood or soft plastic would be like using a Ferrari for your daily ten-minute commute. They would certainly work, but they wouldn’t have an opportunity to show their full potential.
On the other hand, if you need to drill into thick and tough pieces of metal, then you definitely need to get a set. If you have the budget, I recommend going with the premium option, MaxTool’s M42 cobalt drill set.
Otherwise, consider the overall top pick – Irwin M35 Cobalt Steel Drill Bit Set – or the runner-up – Bosch CO21B 21-Piece Set.
Finally, if you are on a budget, go with the DeWalt DWA1240 cobalt drill bit set. While it doesn’t have as many bits as the other sets do – and might be of slightly lower quality – it will do the job in most cases.
Irwin M35 Cobalt Steel Drill Bit Set
A set of 29 cobalt drill bits offering good cost-performance.
