Best Cobalt Drill Bits For Harden Steel That Will Make Your Work Easier!

Drill bits’ sets are designed specifically for certain drilling tasks. Their effectiveness majorly on the materials you are working on. The perfect one for hardened steel or metal comes with a blend of 5%-8% cobalt with alloy. 

This cobalt ensures part of the steel blend, making sure the hardness of the steel doesn’t wear off with a coating such as titanium. It’s all over the entire bit. This also increases its heat resistance and durability. The greatest part of these kinds of bits is that you can sharpen them. However, it will cost you extra money compared to regular bits for metals.

It’s advisable to add a drop of oil when drilling a hole with a cobalt bit to ensure the cutting end cooler as it cuts. Place a piece of wood underneath the steel you’re cutting. This will enable you to cut perfectly through the steel and avoid striking the surface below that may dull your bits cutting edge.

But it doesn’t matter whether you are an expert on this part or just a DIY person learning new skills! It’s significant to have the right tools to avoid wasting time while preventing possible frustration.

Best Cobalt Drill Bits For Harden Steel That Will Make Your Work Easier!

What Are The Best Cobalt Drill Bits For Hardening Steel?

There are several cobalt drill bits nowadays, but we will summarize the top six you can consider. Each has special features and benefits that make them outstanding, making your work easier while choosing the perfect one.

Best Overall Pick:

IRWIN Drill Bit Set, Cobalt Steel,29-piece (3018002)

A durable and super abrasive resistance model that contains 29 pieces to choose from

Best Versatile Option:

NEIKO 01925A Screw Extractor and Left Hand Drill Bit, Cobalt HSS Drill Bits, Alloy Extractor, 10 Piece

A perfect tool suitable for both drilling and screw extractor, the ten pieces are made from alloy, i.e., extractors and drill bits made of cobalt.

Best Finishing Option:

Drill America DwD29J-CO-PC Qualtech Cobalt Steel Drill Bit Set

The model has a black and gold oxide coating that prevents corrosion resistance. It enables you to drill at a higher power setting without tear and wear.

Best For Hobbyist:

Bosch CO14B 14Pc. Cobalt M42 Drill Bit Set

If you enjoy DIY drilling, then this model set is specifically meant for you. It’s one of the best cobalt drill bits we can recommend for a drilling hobbyist.

Best For Budget:

DEWALT Cobalt Drill Bit Set with a pilot point, 14-piece (DWA 1240)

For someone on a limited budget and who needs a quality cobalt drill bit at an affordable price, this will be a perfect tool.

Most Durable:

Hymnorq Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill with Straight Shank (13pcs)

These heavy-duty models guarantee precision drilling across super hard metals like harden steel, cast iron, aluminum, etc. When you compare with the regular ones, the model possesses up to 12 times lifespan.

 Top Six Cobalt Drill Bits For Harden Steel 2021

Here is a complete comparison table of the best six cobalt drill bits that will help you get an overall picture of all of them. Kindly go through it and check every one main feature;

Comparison Chart Of The Best Cobalt Drill Bits For Hardened Steel

Best Cobalt Drill BitWeightSet Size (pc)BestManufacturer
IRWIN Drill Bit Set, Cobalt Steel,29-piece (3018002)4.45 pounds29Best OverallIRWIN
NEIKO 01925A Screw Extractor and Left Hand Drill Bit, Cobalt HSS Drill Bits11.3 ounces10VersatileRidgerock Tool Inc.
Drill America DwD29J-CO-PC Qualtech Cobalt Steel Drill Bit Set2.2 pounds29FinishingDrill America
Bosch CO14B 14Pc. Cobalt M42 Drill Bit SetMy product name1.06 pounds14For hobbyistBosch
DEWALT Cobalt Drill Bit Set with a pilot point, 14-piece DWA12.8 ounces14For budgetDewalt
No products found.4.4 ounces13DurableHymnorq

IRWIN Drill Bit Set, Cobalt Steel, 29-piece (3018002)

The model contains 29 bits made from premium speed steel and 5% cobalt. These bits range from 1/16 to 1/2 inch in 1/64 increments. They are super abrasive resistant, especially when drilling in tough materials. The cobalt-steel combinations extend the bits cutting edge life also. When they start to wear out, you only need to sharpen up for it to go a long way. Irwin drill has a lifetime warranty that covers defects in parts or poor artistry.


Since the bits are made from cobalt steel, they are durable. They are resistant to heat as well. The manufacturer’s model is very popular in this industry for its reputable product with very minimal maintenance. Some other highlighted features of these products include;

1. A 135-Degree Split Point At The Tip: the tips increase efficiency by enabling drilling with less force. Since they always start on contact, the project will be up and running within a short time.

2. Different Size Options:  the model comes in a range of dissimilar size options for numerous applications.

3. Study And Protected Storage Case: the packaging of these bits are great. Those are placed in a metal index case which allows easy identification and access while protecting your bits.


1. Perfect for highly rough materials and can be driven into it easily.

2. Lifetime warranty

3. These bits don’t produce heat when in use

4. Less maintenance and improved cutting edge efficiency.


1. If the bits are not lubricated frequently, they can break.

Technical Details

Item Weight4.45 pounds
Product Dimensions12*7.5*4 inches
Part Number3018002

NEIKO 01925A Screw Extractor and Left Hand Drill Bit, Cobalt HSS Drill Bits, Alloy Extractor, 10 Piece 

These drill bits were designed specifically for the left-hand users in mind. The 10 set drill bits’ ranges from 5/64 to 19/64 inch. Generally, the 10-piece package is divided into two, i.e., five drill bits and five extractors.  These bits are durable and high abrasive resistance of cobalt. In comparison, the screw extractors are made of alloy materials.

These impressive model drills harder materials at a higher speed and less wear. Different design is used on the tip of the screw extractors and bits.


Usually, the drill bits pin-point tip provides a precision start, meaning there is no need for a point hole that causes inconveniences. On the other hand, the extractors have numerous spiral flutes design to dig into the screw easily. Some other outstanding features of these model includes;

1. An Index Carries Case: for convenience and storage, the model comes with an indexed carrying case. A carry handle is placed at the top for easy transportation. The case has a wider base for stability while preventing it from being knocked over.

2. Different Bit Sizes And Screw Extractors: they both come in different sizes design for specific purposes. The sizes are labeled clearly on the case for easy identification of each piece.

3. Wide Application: apart from the bits for the drill, the model case has five different screw extractors. Normally, meant for easy removal of broken screws, bolts, studs, plus other fittings effectively.


1. Durable and affordable design

2. Extra screw extractors

3. pin-point tip for precision start

4. Indexed carry case with handle for easy transportation and identification


1. Since they are meant for left-hand users, right-hand users might have difficulties using these bits.

Technical Details

ManufacturerRidgerock Tool Inc.
Item Weight11.3 ounces
Product Dimensions5.67*4.49*0.79 inches
Part Number01925A

Drill America DwD29J-CO-PC Qualtech Cobalt Steel Drill Bit Set

Drill America 29- piece set is a general-purpose drill because it has the bits you need for any of your projects. Its made with premium quality cobalt constructions, the greatest designs, and extremely sharp and high-performing drills. The jobber length drill bits include sizes 1/16- inch, 1/2-inch, 1/64- inch increments.

These drills come in a plastic index case with labeled compartments for organization and easy identification. The model conforms to American National Standard Institute Standards (ANSI).


Typically, the drill bits are organized spirally in a small canister, giving you an easy time to locate and replace via their labeled slot is broken. The drill bits are very sharp and true to size. The smallest ones also have split points that are not common in several sets in the market. The index case is sturdy and store the bits properly. Other amazing features of the model is as follows;

1. Gold Oxide Finishes: Each bit has a coat of gold oxide finish that enables higher durability. The coating also lubricates the drill bits to ensure more resistance against wear.

2. 135-Degree Split Point: A heavy-duty 135-degree split point is seen on these model bits, which allows quick penetration in hard materials. Furthermore, there is no need for a pilot hole. The model has minimal clogging since the chips generated in the process are very small.

3. High Drilling Speed: the model permit is a drilling speed of up to 30 percent faster.


1. Lifetime warranty

2. Gold oxide coating improves the heat resistance of the bits

3. Cobalt steel increases its durability

4. Comes in a size plastic index for easy identification.


1. The case material quality is not very satisfying.

Technical Details

Brand NameDrill America
Item Weight2.2 pounds
Cutting Angle135 degrees
Part NumberDWD29J-C0-PC
Finish TypeGold Oxide

Bosch CO14B 14Pc. Cobalt M42 Drill Bit Set

For someone who likes working with hard materials such as stainless steel, hardened steel, titanium, cast iron, etc., these 14-piece sets will be good for them. More so, if you don’t need a more extensive industrial set. The model offers high functionality and great performance.

The model is made from cobalt alloy and high-speed steel, with span circumferences of 0.1719 to 0.5 inch, to achieve top strength levels regarding hard materials. 


The quality of the models is ten times durable than that of a standard drill bit. Additionally, the model is complemented by a storage case for convenient transportation. Apart from those features, the model also has;

1. Thick Web-Helix Design: this allows extra stability in some tough applications.

2. Surface –Harden Tip: that allows it to penetrate easily across tough, abrasive materials.

3. High-Heat Resistant Drill Bits: these model drill bits can withstand high-temperature use for longer periods.


1. High heat resistant drill bits.

2. Made with enhanced M42 alloy material to improves its durability

3. Thick wed-helix design for extra stability for tough usage


1. Slightly expensive

2. The carrying case indexing s not easy to read.

Technical Details

Item Weight1.06 pounds
Product Dimensions8.98*4.61* 1.61inches
Part NumberCO14B

DEWALT Cobalt Drill Bit Set with a pilot point, 14-piece (DWA 1240)

The model offers maximum speed and control over the drill bit since there is no bit on metal surfaces. There are rare hardened steel bits sets that offer such user-friendly options.

This 14-piece set made from industrial cobalt is design for drilling over hard metal. The sizes range from 1/6 inch to3/8 inch, which is suitable for any project.


Dewalt drill has a connectable accessory storage system to maximize the storage space of bits for metal, woods, or I-beams. These are some more features;

1. M35 Grade Cobalt:  these bits are made using M35 grade cobalt to ensure they remain sharp for some time.

2. Split Tip And Point Design: which cut across harden steel for any projects.

3. Small Bulk Storage Size normally fits inside the small and medium tough case, perfect for organizing loose bits.

4. The Pilot Point Tip begins as the contact for clean, minimal lock-up, precise holes on breakthrough.


1. Lon-lasing bits.

2. pilot point tip offers no walking

3. Many bits’ sizes with regular inch variants

4. Clip latch for more secure closing.


1. The model case is incredibly flimsy.

Technical Details

Item Weight12.8 ounces
Product Dimensions8.75*1.74* 8.75 inches
Part NumberDWA1240

Hymnorq Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill with Straight Shank (13pcs)

 Hymnorq metric M35 is a heavy-duty drill that guarantees precision drilling across extremely hard metals such as cast iron, hardens steel, etc. Its lifetime is estimated to be twelve-time than that of a standard high-speed drill bit.

The 13-piece set covers holes around 1.5 to 6.5 millimeters in diameter. If there is proper maintenance and storage of these drill bits, they’re likely to withstand the most stubborn materials.


The model has a 135-degree split-head and quick-cut points first self-center. Enabling it to penetrate with less pressure for reduction with minimal pressure for less friction and heat. Other features include;

1. Downloadable User Guide:  you can download some tips on drilling metals, articles, and a PRM chart on the internet. These tips will help you gets better results.

2. A Plastic Indexed Storage Case maximizes efficiency and proper storage of the drill bits plus easy transportation.

3. 13 PC Metric Bits:  these 13- piece cobalt steel M35 twist drill bits set include; 6.5mm,5.5mm, 5mm, 4.5mm, 4mm, 4.5mm, 4mm, 3.2mm, 3mm, 2.5mm,  2mm, etc.


1. No center punch is needed.

2. A durable model that lasts twelve times than a common drill.

3. A downloadable user guide makes your work easier.

4. Superheat-resistant model.

5. Faster drilling penetration across hard metals.


1. It must be used and operated at proper PRMs for high efficiency.

Technical Details

Item Weight4.4 ounces
Product Dimensions5.12*0.59* 2.76 inches
Part NumberDC023

What To Consider When Choosing The Perfect Cobalt Drill For Harden Steel

There are many cobalt drill bits available nowadays though all of them don’t have the same results. To achieve the greatest result, you need to identify the suitable drill bits that will perform the task perfectly. We know the process of looking for such tools might be overwhelming and tiresome, especially if it’s your first time. Well, we have done thorough research, and here are some factors you need to consider while buying the cobalt drills;


Different manufacturers complement materials such as drill bits with metal coatings. These coatings improve the protection and penetration of these drill bits. Some coating reduces heat and friction when drilling, while other offer protection against corrosion and water.

Drill Bit Numbers/Size

Drill bit number/ size is a significant factor when purchasing drills for hardened steel. The drill bit size is related to the wire gauge size. When the bit number is large, the diameter of the resulting hole will be small. So, while the diameter grows bigger, the bit number grows smaller.

The drill size in your hard steel is crucial to picking the right drill bit for your task.

Flute Design

Flute refers to the deep groove that twists around the bit, and it’s used to give waste materials a way out. They are two major types of flute design that you need to know, i.e., parabolic flute design and 30-degree angle design.

The parabolic flute design is highly recommendable for someone cutting through a softer material. At the same time, a 30-degree angle design is meant for drilling through hardened steel.

Drill Point Length And Angle

This consideration is closely related to drilling bits’ design. We will talk about the drill point length first, i.e., what needs to differ in certain material you are working on. If you’re working with metal, shorter drill bits will be perfect since they are more rigid and enables higher accuracy. You’ll run the risk of breaking the bits with longer ones.

On the other hand, the common angle is 118 degrees. But, if you want fast drilling, then a 135-degree self-centering angle is the right one. More so, if you. Reworking on a steel surface.


Most of the time, price is a determining factor; it doesn’t matter the kind of product you are buying. Sometimes you might be interested in a certain product, but your budget is limited, forcing you to settle for another one fitting your budget. So, as much as you want certain features in your drill bit, consider your budget to pick the suitable out of the available options. Some models are affordable and offer great services. 


You should as well pay attention to the quality of this product. Yes, cobalt drill bits are made from cobalt but at what percentage?  There are three ways commonly known for assessing product quality. The first one is the type and percentage of cobalt within the bit and reputation of the brand that makes them. Lastly, the positive, neutral, and negative reviews from various customers.

All the products that we have rated in this article were also based on these three ways, and gladly they made it out. Quality products cost slightly higher than the standard ones, but they are worth it at the end of the day.


Will it not be better to find a product that does more than one thing in a set! We thought so too. Mostly these tools come in set with many pieces of different sizes and applications. The more pieces, the better for you, although it’s good to purchase what you need. But if you normally use most of these pieces, it’s better to buy them at asset.

It’s important to know the number of bits the set has, their quality, and purpose. There are set with 12, 29 pieces, and so on depending on the manufacturer and the price.

Working Frequency

Drilling metal at high speed creates excessive heat and frictions, which tend to wear them quickly. If you are planning to use your product frequently, consider buying bits designed with longevity in mind.

On top of protective coatings and extra-hard materials, drill bits’ users seeking durability should make sure to sharpen the bits. As for cobalt or carbide drills, they usually keep their edges longer than regular bits. Investing in such a set means you will be sharpening dull drill bits more often.

Frequently Asked Questions

1. What Is A Cobalt Drill Made Of?

As their name suggests, they are made from cobalt; that’s not the case. Rather, cobalt drill bits are made from premium-speed steel that contains a specific percentage, normally 5% to 8% of cobalt. The share is enough to penetrate many, if not all, hardened steel which is also helpful for stainless steel.

2. Which Is A Better Drill Bit For Hardened Steel Between Cobalt And Titanium? 

Titanium drill bits are more durable than cobalt ones, although they’re overly expensive. While on the other end, cobalt bits are very useful and design particularly for drilling into abrasive materials such as cast irons, stainless steel, and titanium. A cobalt drill bit with a titanium coating is perfect for boat words as they’ll cut across anything.

3. Are Cobalt Drill Bits Worth The Money?

Yes, if its main task is to drill through-hardened steel, it’s worth the money and the struggle. Typically, this type of drill is very powerful and can drill through hardened steel with ease. On top of that, it enables accurate holes as well as comfortable drilling ways. Cobalt’s drill bits are also pocket-friendly and durable. When you properly maintain them, it will give service for a longer period. Investing in them a pretty idea since it will pay off in the long run.

4. Can Someone Use Cobalt Drill Bits With Wood?

Yes, it’s possible, but it will be too much. We recommend the use of standard speed steel bits for that task. Reserve your expensive cobalt drill bits for drilling through hard materials like metals.

5. Can I Sharpen My Cobalt Drill Bits?

Yes, you can more so because they’re made using quality materials. Usually, cobalt drill bits tend to stay sharper for quite a while than other types, assuming similar usage. Since cobalt drills are used in tougher conditions, you might need to sharpen them now and then. Bench grinders are among several other ways you can use to sharpen your bits.

6. Do I Need To Lubricate My Cobalt Drill Bit Whenever I Use It?

It’s always recommended to use premium quality or cutting oil when drilling metals. Oil will help reduce friction for smoother and faster drilling while prolonging its life of service. At the same time, it prevents heat buildup and spark, which often happens with metal to metal contact. But, when drilling through wood or plastic, lubricant is not needed.


Drilling through hardened steel seems like a tough job, but it can be surprisingly easy when you have the right tools. To drilling through-hardened steel, you will need a heavy-duty drill bit design to pierce through these materials effectively and efficiently. 

Always use specific tools design for that task, or you might run the risk of damaging your project, drill, and a bit. It can be challenging to choose a perfect one between a wide variety of bits available on the market, and that’s why we have prepared this article to help you out. With either a bigger or smaller budget, ensure you will get a suitable tool to handle the task ahead and avoid possible frustration.

Last update on 2023-02-24 / Affiliate links / Images from Amazon Product Advertising API

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