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7 Best Cobalt Drill Bits

There is no better bit for metal drilling than a cobalt drill bit.
Drill Bits
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For the drilling duties to be completed successfully, you need access to the best drill bits. Cobalt steel, carbon steel, high-speed steel, carbide, and titanium-coated drills are some of the varieties of drill bits produced throughout the years by various manufacturers. These drill bits come in a variety of different sets.

Various bit materials are available, each with its advantages and disadvantages. However, when discussing cobalt drill bits, it becomes clear that they are the most effective at penetrating rigid materials and that their longevity is also exceptional.

7 Best Cobalt Drill Bits

What are Cobalt Drill Bits?

Cobalt drill bits, including stainless steel, are specifically designed to cut through hard metals. Unlike conventional drill bits, they have a higher heat and abrasion resistance because of the five to eight percent cobalt blended into their high-speed steel material. 

This makes them an excellent choice for drilling through rigid materials like hardened steel, cast iron, titanium alloys, and other difficult-to-cut metals.

Cobalt drill bits generally last longer than regular high-speed steel (HSS) drill bits due to their increased hardness. The added cobalt also allows them to retain sharpness at higher temperatures better than HSS drills – making it possible for cobalt drill bits to handle more demanding workloads with less downtime for sharpening.

A ½-inch cobalt drill bit is essential for any serious DIYer or professional contractor working with metal. These drill bits are made of a blend of high-speed steel and cobalt, which makes them more resistant to wear and heat than regular HSS bits. 

The high-quality construction also makes these bits ideal for drilling through hard steels like stainless steel, titanium alloys, and even hardened metals. When you need precision accuracy for your drilling jobs, ½-inch cobalt drill bits deliver the power and results you need to get the job done right. Plus, they’re compatible with most standard ½-inch drills, so you can easily add them to your existing toolbox. 

Cobalt drill bits are an excellent choice for drilling through hard materials, with improved longevity and high heat resistance. They can be more expensive than regular HSS drill bits, but they offer the advantage of not having to be replaced as frequently – resulting in a cost-effective solution in the long run.

Different Kinds of Drill Bits Made of Cobalt:

There are four varieties of cobalt drill bits, each designed to perform a specific function. It is necessary to have a good understanding of the appropriate application for each bit type.


Drill bits, known as twist bits, are designed for general drilling purposes and may be used to bore holes in various materials. They have slanted grooves that wind their way around the drill shaft in a spiral pattern. 

These angles have sharp edges, which enable the bit to penetrate deeper into the material being worked on. Cobalt twist bits have the strength necessary to bore through tough metals swiftly. They are available in a broad range of sizes, with some sets including as many as 30 individual pieces.


Countersink drill bits are used to make shallow holes that are inclined to match the curved head of the fastener. This allows the head of the pin to sit flush with the material it is using. 

Countersink bits made of cobalt can generate holes in hard metals with a countersunk appearance. To drill into a substance, countersink bits demand that there already be a hole there first. This contrasts to twist drill bits, which have tips that can pilot themselves. 

First, twist bits are used to drill the primary hole, and then countersink drill bits are used to make the actual countersink holes. Drilling holes with countersinks requires both types of bits.


Counterbore drill bits make holes in a material that enable the head of a fastener to be positioned below the material’s surface. In contrast, to countersink bits, counterbore drill bits produce a wider hole at a shorter depth. 

Countersink bits make an angled hole for fasteners with angled heads. A spot that has been counterbored produces a flat ridge that can accommodate the fastener’s head.

Cobalt Step:

Step drill bits made of cobalt are specifically developed to make holes in sheet metal. The cone-like design of a step bit causes it to grow the spot as it passes through the sheet metal. This allows users to control the diameter of the hole they create. 

The maximum thickness of sheet metal that can be cut using a step bit is one-quarter of an inch. The use of a step bit should be considered by anyone wishing to drill through sheet metal at short depths.

What you Should look for in Cobalt Drill Bits and How to Choose Them: Buying Guide

DIYers will want to examine a few more factors, such as the drill bit’s size and the amount of cobalt it contains, in addition to knowing what kind of drill bit is required for the task. Customers looking for cobalt drill bits will want to ensure they understand the project’s requirements before purchasing the first pair of cobalt drill bits they come across.

Tips for Buying and Using Cobalt Drill Bits:

It is essential to consider the following advice before purchasing or utilizing a cobalt drill bit.

  • Don’t toss out those dull drill bits just yet. Instead, restore their razor-sharp edges by grinding them down using a grinding wheel.
  • Cobalt bits are too strong to drill holes in wood or other materials. Therefore, you should only use them for drilling holes in metal.
  • When working with cobalt drill bits, because the process of drilling through steel, cast iron, and other metals creates microscopic shards that have the potential to penetrate your skin or eyes, it is essential always to wear protective gloves and safety glasses.

Best Cobalt Drill Bits (Full Comparison)

Our Best Picks for Top 7 Cobalt Drill Bits:

BOSCH CO14B 14 Pc. Cobalt M42 Drill Bit Set

BOSCH CO14B 14 Pc. Cobalt M42 Drill Bit Set

  • Material: Stainless Steel, Cobalt
  • Shank Type: Straight
  • Brand: BOSCH
  • Tool Flute Type: Spiral
COMOWARE Cobalt Drill Bit Set- 29Pcs

COMOWARE Cobalt Drill Bit Set- 29Pcs

  • Material: M35
  • Finish Type: Titanium
  • Shank Type: Straight
  • Cutting Angle String: 135 Degrees
  • Brand: COMOWARE
Amoolo 1/4

Amoolo 1/4″ Cobalt Drill Bit(10 Pcs)

  • Material: Cobalt Steel
  • Cutting Diameter: 0.25 Inches
  • Shank Type: Round
  • Cutting Angle String: 135 Degrees
  • Brand: Amoolo
Drill America - DWD29J-CO-PC 29

Drill America – DWD29J-CO-PC 29

  • Material: Cobalt
  • Finish Type: Gold Oxide
  • Shank Type: Round
  • Cutting Angle String: 135 Degrees
  • Brand: Drill America
DEWALT Cobalt Alloy Drill Bit Set

DEWALT Cobalt Alloy Drill Bit Set

  • Material: Stainless Steel
  • Finish Type: Cobalt Alloy Steel
  • Shank Type: Straight
  • Brand: DEWALT
Craftsman Cobalt Drill Bit Set

Craftsman Cobalt Drill Bit Set

  • Item Weight: ‎1.27 pounds
  • Size: ‎21-pc
  • Manufacturer: Craftsman
  • Material: ‎Cobalt
IRWIN Drill Bit Set

IRWIN Drill Bit Set

  • Material: Cobalt
  • Finish Type: Cobalt Alloy Steel
  • Shank Type: Straight
  • Cutting Angle String: 135 Degrees
  • Brand: Irwin Tools

1. BOSCH CO14B 14 Pc. Cobalt M42 Drill Bit Set

This set from Bosch is equipped with M42 drill bits, making it capable of drilling through the most challenging metals. The eight percent cobalt alloy is more robust than the cobalt alloy used to make M35 cobalt drill bits, resulting in a longer shelf life for the eight percent cobalt alloy. 

The metal may be easily drilled through, thanks to the other features included in this package. While a flat shank helps prevent slippage in the chuck, a split-point tip makes it easier to pierce through metal. 

These Bosch bits have more extensive threading than the majority of spiral drill bits, which is a design that is intended to remove material more effectively and lessen the amount of time required to drill into metal. This set has 14 pieces, varying in size from 1/16 inch to 1/2 inch, and it can be purchased here.

The Bosch cobalt drill bits featured a one-of-a-kind mix of structural characteristics and extra hard M42 alloy, which made them a joy to work with. These features and alloy made them exceptionally durable. 

To evaluate this device, we put a cordless drill and a drill press through their paces. This allowed us to compare the results of handheld drilling with the more precise work of the drill press. 

The cordless drill performed satisfactorily in most respects, but the variable-speed trigger made it more challenging to keep the speed at a modest and accurate level while drilling steel.

In general, however, we found the split-point tip and 3-flat shank quite helpful because they allowed for stable chucking, smooth drilling, and simple sharpening. 

Before being sharpened, these M42 test bits kept their edge sufficiently enough to allow us to drill the second series of test holes using the drill press before they needed to be sharpened. 

Because it had a split point, sharpening was also a simple process. The additional control these bits’ design made possible was notably beneficial while drilling into brittle and complex cast iron because of the latter.

BOSCH CO14B 14 Pc. Cobalt M42 Drill Bit Set
MaterialStainless Steel, Cobalt
Shank TypeStraight
Tool Flute TypeSpiral
  • A split-point bit’s longevity can be increased by simply sharpening it.
  • Reduces the risk of the drill bit sliding in the chuck thanks to its three flat sides.
  • The cobalt alloy known as M42 is more durable and practical than its predecessor, M35.
  • The kit comes with the most commonly used drill bit sizes.
  • The case’s bit size labels are nearly impossible to see.

2. COMOWARE Cobalt Drill Bit Set- 29Pcs

This is an exceptionally high-quality drill bit set that was made to last for more years of service in contrast to other drill bit sets. This tool set’s longevity is increased thanks to high-speed steel M35 and cobalt (5%), which are included in its construction.

This item features a gold oxide finish, and its circular, straight shanks offer much practicality. The fact that it has been thoroughly ground ensures that the chips slide without friction.

The COMOWARE Drill Bit Set is a product that has been expertly crafted and is well-suited for drilling into materials that have been hardened. It can slice through various rigid materials, such as cast iron, Titanium alloy, stainless steel, wood and hard plastic, and high-heat alloy. It is also appropriate for use with some types of soft materials. 

The overall mass of this set is 12.8 ounces, and the measurements of this instrument are as follows: 7 inches in length, 5.1 inches in width, and 2.4 inches in height.

COMOWARE Cobalt Drill Bit Set- 29Pcs
Finish TypeTitanium
Shank TypeStraight
Cutting Angle String135 Degrees
  • Its precise split point at 135 degrees should be mentioned here.
  • This is a tool that experts use, and it will make your job a lot simpler for you to do.
  • This equipment is more suited to working with challenging materials than softer ones.

3. Amoolo 1/4″ Cobalt Drill Bit(10 Pcs)

The pricing of this 13-piece set of cobalt drill bits from Amoolo is a quarter of the price of comparable groups of cobalt drill bits. This set is robust because the cobalt steel alloy makes up 5 percent of it, but it is less intense than M42 pieces, which make up 8 percent of the alloy. 

The longevity of these pieces can be increased by using a lubricant or cooling water regularly. Their split-point tips eliminate the need for walking and make it simpler to begin holes. These bits come packaged in a plastic container labeled with their sizes, and their dimensions range from 1/16 inch to 1/4 inch.

In the tests we undertook, the Amoolo cobalt drill bits worked just as well as some of the most well-known brand names, but they were far more affordable. They drilled smooth and clean holes, and it was simple to match the 135-degree split point with the bench grinder so it could be sharpened. 

However, it is essential to note that the kit only offers smaller bit sizes in increments of 1/16 of an inch, making it an excellent choice for drilling patterns requiring a high level of detail.

The only drawback we saw was the thin plastic container and foam bit holder; these gave off the impression that they were meant for shipping rather than serving as components of a protected carrying case. 

However, could anyone tell the difference from a functional standpoint if we were to replace a few of their Irwin cobalt drill bits with these?

Amoolo 14 Cobalt Drill Bit(10 Pcs)
MaterialCobalt Steel
Cutting Diameter0.25 Inches
Shank TypeRound
Cutting Angle String135 Degrees
  • Cost-effective option for industrial-strength drill bits
  • The sizes of the bits may be found in millimeters and inches.
  • Includes 13 drill bits ranging from 1/64 inch to 1/2 inch in diameter.
  • For continued use, split points may be easily resharpened.
  • Lightweight plastic and foam casing that isn’t very sturdy.

4. Drill America – DWD29J-CO-PC 29

Is your drill generating a significant amount of heat while it’s working? Are you seeking a superior alternative that can get rid of this problem? Then, consider the information provided below regarding the Drill America DWD29J-CO-PC Qualtech. The thermal resistance of the tool is improved by the coating of gold oxide that is applied over the surface of the cobalt steel.

Because the bits feature a self-focusing 135-degree split point, it is not necessary for you to produce a pilot hole before beginning the operation. These bits have applications across a wide variety of machine types. 

As a result of the availability of the twisted area, there is no risk that the drill bits will become bent. Because it is available in various dimensions, it may be utilized for several demanding applications.

Drill America - DWD29J-CO-PC 29
BrandDrill America
Cutting Angle String135 Degrees
Shank TypeRound
Finish TypeGold Oxide
  • Bit durability and performance are both improved by using cobalt steel.
  • A layer of gold oxide improves the bits’ heat resistance.
  • A size index is included to locate the appropriate bit size for the task quickly.
  • Thanks to the 135-degree split point, a pilot hole isn’t necessary even when working with rigid surfaces.
  • The casing material is of subpar quality.

5. DEWALT Cobalt Alloy Drill Bit Set

Another brand that emphasizes both quality and value is DeWALT. They are a shining example of the American dream come true and are revered worldwide as industry pioneers in producing tools and accessories.

Because these bits are designed with a pilot point, it is less probable that a pilot hole will need to be bored before using them. They also have a lower probability of walking across the metal’s surface. The sizes vary from 0.062 inches up to 0.375 inches, which means that the range of applications is less broad than that of the Drill America set, but there is still sufficient variety to suit most tasks.

This set is M35 grade because it includes 5% cobalt and is designed for hard metals such as stainless steel, metal, and I-beams.

DEWALT Cobalt Alloy Drill Bit Set
MaterialStainless Steel
Finish TypeCobalt Alloy Steel
Shank TypeStraight
  • Pilot point design.
  • No need to drill pilot holes.
  • Great price.
  • M35 grade.
  • Limited size range.
  • 5 percent cobalt.
  • Build quality issues.

6. Craftsman Cobalt Drill Bit Set

The Craftsman Cobalt Drill Bit Set comes in helpful when it comes to the more challenging chores. If you spend each day working with rough surfaces and heavy metals, then using this man will almost surely cut down on the effort you need to put into the job. 

In addition, the bit set has a size index, which allows you to select the appropriate size of bit for the operation without having to worry about being confused about the various sizes.

The precision of the drilling is improved because of the feature known as the split point. The bit set is conveniently packaged in a plastic container, making it simple to transport. In addition, a wide variety of sizes of bits are available to you. As a result, your tool is capable of doing numerous tasks at the same time.

Craftsman Cobalt Drill Bit Set
Item Weight‎1.27 pounds
  • For projects that call for a high-pressure drill, it comes in quite helpful.
  • Tools like the hand drill and the drill press are a good fit.
  • The need for a pilot hole is avoided, and the bit stays in place thanks to its improved split point.
  • It may be applied to various metal surfaces and rough textures.
  • The bit’s lack of a notch at its end makes it difficult to maintain a firm hold and forceful enough to break through particularly resistant materials.

7. IRWIN Drill Bit Set

Irwin has produced a 29-piece set that should interest anyone who needs bits in various sizes. These twist drill bits come in sizes ranging from 1/16 inch to 1/2 inch, with increments of 1/64 inch between each length.

Each bit has a split-point top, which simplifies the process of making a hole in the material. To provide a longer service life under demanding drilling circumstances, M35 alloy bits are constructed from a steel alloy that contains 5% cobalt.

Many people who do home repairs may relate that loose parts soon become missing bits. Irwin is aware of this, and as a result, this set comes with a practical carrying case that safely indexes all 29 bits into three distinct cartridges. These cartridges, in turn, fit neatly into a robust rubber molded box that can be carried around easily.

Both before and after being sharpened, the Irwin M35 drill bits operated admirably; after drilling the first three holes, the bit had just slightly lost its edge. 

These bits produced smooth and clean holes, regardless of whether or not a center punch was used to mark the positions of the holes. Additionally, aligning the split point at the appropriate angle on the grinder was simple so that it could be sharpened.

Although the total weight of the metal box and 29 bits was considerable, we particularly loved the bit case for its ordered storage. However, it is most suited for a workshop setting. 

This set is an excellent option for individuals who want precise drilling for a range of tasks since it comes with a large selection of sizes that can be adjusted by 1/64 of an inch. On the other hand, for people who would only utilize these bits sporadically, the higher price may not be justified, given the limited utility of the product.

IRWIN Drill Bit Set
Finish TypeCobalt Alloy Steel
Shank TypeStraight
Cutting Angle String135 Degrees
BrandIrwin Tools
  • The valuable life of a split point bit can be significantly increased by its ease of re-sharpening.
  • There are a few substances of M35 cobalt alloy cannot be used.
  • For more precise drilling jobs, this 29-piece set provides additional incremental sizes.
  • Packaged in a sturdy steel container with a drill and tap selection guide.
  • Expensive, but well worth it for the quality.
  • The bulky carrying case is inconvenient while going to and from work.

Frequently Asked Questions:


You should consider cobalt drill bits if you have a project that requires drilling through hardened steel or any other material that is smooth and durable. The drill bits stated above are widely regarded as the best cobalt drill bits; hence, you should pick them without any reservations.

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