Best Cobalt Drill Bit Set – My Top 3 Picks!

Every DIYer should have a trusty set of drill bits on their toolkit. Instead of wasting your money on cheap tools, you might as well invest in the best cobalt drill bit set. Unlike typical stainless steel, cobalt bits are twice more durable. It’s also a specialized drill bit made for drilling on treated cast iron, stainless steel, and even titanium. If you’re looking for the best cobalt bits to buy, you’ll never go wrong with these three picks:

 Our Top Pick! 
COMOWARE 115-Piece
Cobalt Drill Bit Set
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IRWIN 29-Piece
Drill Bit Set
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Chicago Latrobe 29-
Piece Drill Bit Set
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What are cobalt drill bits?

Cobalt bits are used for heavy-duty drilling. Unlike typical stainless steel bits, those made of cobalt have higher drilling power. It can bole holes on metals, something that plain steel can’t do. Still, cobalt remains versatile since it can be used on softer materials as well.

Moreover, cobalt drill bits have a dull, gold color, which makes it stand out among other steel bits. Such a color occurs when the metal is baked. This means that the color of the bits is not plated, but a natural hue that occurred during production. However, this color may fade overtime, especially after repetitive sharpening.

Although it’s called ‘cobalt bits’, such drill bits are not really made of pure cobalt. It’s an alloy of steel and about 5% to 8% cobalt. This fusion is intended to boost the strength of the material so it can put up against tougher surfaces.

If the drill bit has 5% cobalt, it’s regarded as M35 grade while 8% cobalt is rated as M42 grade. The higher the cobalt content, the tougher the drill bits are. Also, the cobalt content of these drill bits is mixed through and through. With this, you can re-sharpen the bits while retaining its durability and strength.

Aside from force resistance, cobalt bits are also heat-resistant. Such a characteristic is important since drilling at high speeds will build up excessive friction and eventual heat. Aside from the cobalt content, the drill bits are also rated based on the temperature it can withstand. Some of the toughest cobalt drill bits can endure up to 1,100F.

Tips in using cobalt drill bits

Since cobalt bits are way stronger than stainless steel, you should know how to use it. The following are some of the points to keep in mind:

✔️Avoid overheating. As a tough option, cobalt bits can withstand high speeds and hard surfaces. However, since such nature will result in higher friction, you must ensure that the bits will not overheat. The concern here is on the drill and not much on the bit. Most cordless drills may not keep up with the endurance of the cobalt drill bit.

✔️Keep it sharp. For more efficient drilling, you can always sharpen your cobalt drill bits. You can use regular cutting fluid to do this. The only thing that the cobalt drill bit may lose is its color but not its strength.

✔️Wear protective equipment. Cobalt bits are reserved for tougher jobs like drilling through thick and solid metal. Such a level of work will also expose you to a higher risk of injuries. This is why you should always wear protective gears.

Cobalt vs. carbide vs. titanium bits

When it comes to strength, the likes of carbide and titanium are often compared to cobalt. In terms of surfaces to drill, cobalt is used on hardened steel while tungsten carbide is usually reserved for masonry. Meanwhile, titanium drill bits are suitable for softer surfaces like soft metals, wood, and even plastic.

Unlike cobalt, titanium drill bits will soon lose its coating, which will affect its heat resistance. On the other hand, tungsten carbide has a higher heat resistance than cobalt. However, full-bodied carbide bits tend to be more brittle, so they are suitable for automated use only.

In terms of price, carbide bits are the cheapest followed by titanium then cobalt. Anyway, it also boils down to the grade of the bits based on their alloy composition.

How to choose cobalt drill bits

Drill bit types

Each bit differs on its construction, which dictates the quality and appearance of the hole it will make. The following are the possible drill bit types you can see within a cobalt set:

✔️Twist drill bit. This is the most common and used for general purposes like drilling on light metal.

✔️Auger drill bit. This one has a screw tip and a spiraling body. It’s used on drilling through thick and hardwood.

✔️Installer drill bit. With this type, you will get a long bit of up to 18 inches that can drill through masonry and plaster.

✔️Step drill bit. This one has a pointed construction with marked steps so you can drill holes on different diameters without switching bits.

✔️Drill saw bits. This bit is used to cut irregular holes on metal or wood.

✔️Spade bit. This one has a flattened blade and a pointed tip. This allows you to create a neater hole.

These are just some of the bit types you can get in cobalt versions. It depends on what you need for your DIY projects.

Size of the set

Once you have decided what bit types must be included in the set, the next thing to consider is the actual size of the set. Drill bits can be bought in 1 to 100+ pieces at a time. If you’re an avid DIYer who works with different materials, you may need a larger cobalt drill bit set.

For newbies, I don’t recommend jumping into a large set right away, unless you don’t mind splurging. It’s best to discover what you need then expand your collection from there. But if you don’t want that hassle, you can always purchase a set right away then work your way around it.


One of my pet peeves is a large drill bit set without a reliable toolbox. The last thing you want is missing a few pieces along the way until the whole set dwindles by itself.

As much as possible, look for a cobalt drill bit set bundled with a sturdy box. It doesn’t matter if it’s a tin can or a high-end, molded toolbox. As long as the container holds everything, it should work. Anyway, it doesn’t hurt to add a few more bucks to get an aesthetic and long-lasting toolbox for your bits.

Best Cobalt Drill Bit Set – My Top 3 Picks!


MY TOP PICK: COMOWARE 115-Piece Cobalt Drill Bit Set
best cobalt drill bit set

Product Name: COMOWARE 115-Piece Cobalt Drill Bit Set

Product Description: If you’re looking for a cobalt drill bit set for the money, you should invest in the COMOWARE 115-Piece Cobalt Set. It has 29 fractional sizes available in 1/16”to ½” inches. Overall, this is available in #1 to #60. Each bit on this set is made of HSS with 5% cobalt (M35) for the highest abrasion and heat resistance. It also has a precise 135-degree split point and twist design. This prevents the bit from chipping, walking, and damaging fast. Moreover, you can use this drill bit set in drilling holes in cast iron, stainless steel, and hard plastics. You can also use this on hardwood. The smaller bits can be used on softer materials.

Offer price: $$$

Availability: InStock

  • Quality
  • Value for Money
  • Ease of Use
  • Durability


If you find the 115-piece set intimidating, you can always start with the 13 or 21, or 29-piece sets. All of these are kept inside a drill bit holder. Inside the toolbox, there are size indexes so you can easily stash each bit easily.

The good thing about this drill bit set is that the sizes are exactly what you use on most DIY projects. You can never go wrong with this quality on a variety of materials.


Split point and twist design

Suitable for both soft and hard surfaces

Comes with an organized holder


Dulls faster but you can always re-sharpen before each use


IRWIN 29-Piece Drill Bit Set

best cobalt drill bit set

If you’re on a budget, you should consider the IRWIN 29-Piece Drill Bit Set. This one has 29 pieces of cobalt bits that are between 1/16 and ½-inch with 1/64 inch increments. Aside from that, each bit has a 135-degree split point to reduce walk while drilling.

The IRWIN drill bit set has 5% cobalt (M35), which can resist abrasions and higher heat. It also possesses heavy-duty web construction that boosts its durability and strength.

Aside from the high-quality drill bits, you will also receive a rubber-molded case. Inside the case are removable cartridges that let you take out a series of bits without it getting lost. There’s also automatic indexing to make it easy for you to identify and access each bit.

Overall, the bits cut like butter even on a drill press. Each bit is very sharp and tough, which makes it easy to penetrate hardened surfaces. If you don’t want the extra sharpness, you can always nibble it away. Also, I like the range of sizes, which makes it useful across DIY projects. It’s also useful for commercial purposes.

  • Drills like butter
  • Comes with case and cartridges
  • Higher heat and abrasion resistance
  • None so far

Chicago Latrobe 29-Piece Drill Bit Set

Lastly, I recommend the Chicago Latrobe Drill Bit Set. It’s composed of 29 pieces of cobalt bits with sizes ranging from 1/16” to ½”. These bits have increments of 1/64 inch. Unlike typical steel bits, this cobalt steel alloy is more long-lasting and resistant to regular use.

Each bit on this set has a gold oxide finish that also works as lubrication against ferrous materials. The bits are also self-centering at a 135-degree split point. With this, you can drill without pilot holes needed. It will also reduce clogging and chipping when working on hardened surfaces.

Moreover, each bit on this set has an extra thick web to make it more rigid and durable. You can also use this on both dry and wet drilling.

Aside from the bits, you will also receive a metal container with engraved indexing. This will help you store the bits properly. It also has removable cartridges that let you bring the bits into the workplace without having to stash it in your pockets.

  • Gold oxide finish
  • Extra thick web for added rigidity
  • Ideal both wet and dry drilling
  • The case can make use of improvements

Frequently Asked Questions

Q: Which is better, M35 or M42 cobalt?

A: M35 and M42 cobalt consist of 5% and 8% cobalt, respectively. Between the two, M35 cobalt drill bits tend to last longer. Still, M42 is also durable since it has a very high heat resistance and heat-treated hardness of up to 70 HRC.

Q: Are titanium bits better than cobalt?

A: Choosing between titanium and cobalt bits are like comparing apples to oranges. Both these two bits are useful and made for specific surfaces. While cobalt is stronger than titanium, it can’t drill through softer materials. Depending on what you’re drilling, both titanium and cobalt could be ideal.

Q: Can you use cobalt drill bits on wood?

A: No, cobalt bits are not made for wood, unless the bit has a smaller diameter. Its extreme hardness and high-speed nature make it produce more heat faster. This can damage wood materials. If you need to drill into wood, you should get a titanium drill bit instead.

Q: What are cobalt drill bits used for?

A: Cobalt drill bit is used when drilling into hardened surfaces like cast iron, bronze, stainless steel, titanium, and other metals. You can also use a cobalt drill bit to cut through welded seams. But since it’s a high-powered drill bit, cobalt isn’t fit for soft surfaces like wood or plastic.

Q: Are cobalt drill bits radioactive?

A: While cobalt is not radioactive, it’s actually good in absorbing radioactivity. The good thing about cobalt bits is it can help reduce radioactive situations so it will not prosper. It’s safe to use as long as applied on the right surface.

Final words 

The best cobalt drill bit set is an excellent addition to your toolkit. It will let you drill through hardened metal with ease. With the proper size and type, you can bore holes into tough surfaces as smooth as butter.