Black Oxide VS Cobalt Drill Bits – Which is the best?

There are many types of drill bits, but there are two main categories: hard material bits and soft material bits. Hard materials include carbides, diamonds, and cubic boron nitride (CBN). These bits work by creating heat as they break down or wear away the surface layer of your drilling component.

Hardened steel is one of the most common materials used to make drill bits. When hardened properly, it is called black oxide hardening, which causes the tip to appear darker. This process requires very high temperatures to take place, so only solid metals can be worked with white oxide until it has been removed.

Drill bits made out of pure cobalt exist and perform similarly to carbon steel ones, however, they are considerably more expensive due to the amount needed per piece. Therefore, they are only manufactured in limited quantities and sold at premium prices.

Soft material drill bits contain composite materials such as ceramic or plastics mixed with glass fibers. These materials are less efficient than harder substances at producing heat, making them less effective for certain uses.

History of cobalt

As we mentioned before, drilling is an integral part of any metalworking process. While some metals do not require too much effort to drill, others are more difficult to work with due to their thickness or hardness.

Drilling can be done using either a hand tool or a machine tool. Drills are typically made out of ceramic or carbon steel, but some advanced drills are crafted from special alloy materials that only exist in very limited quantities.

One such material is called black oxide (also known as pyrolusite). It consists of extremely hard, gray-colored crystals that grow in sheets. The density of this crystal is over ten times greater than a pure nickel!

Cobalt is one of the most common additives used to form these black oxides. Because it is so expensive, manufacturers must use extreme caution when handling and storing it. This includes keeping it away from water and other reactive substances.

When these precautions are taken, there is almost no risk of corrosion or poisoning. However, if they are mishandled or exposed for longer than needed, then harmful compounds can develop. These include hydrogen gas and cyanide which both pose serious health risks.

Differences between Black Oxide And Cobalt Drill Bits

Black oxide and cobalt drill bits are both types of drill bits that are used for drilling into various materials, such as wood, metal, and plastic. However, there are some key differences between the two:

Material:

Black oxide drill bits are made from high-speed steel (HSS), while cobalt drill bits are made from cobalt steel. Cobalt steel is more heat-resistant and durable than HSS, making cobalt drill bits more suitable for drilling into harder materials, such as stainless steel and cast iron.

Hardness:

Black oxide drill bits are not the same as high-speed steel (HSS) bits. They are made by heating regular HSS bits to a high temperature of 950 Fahrenheit, which creates a black oxide finish. This process can soften the HSS bits and make them less hard than cobalt drill bits. 

Cobalt drill bits are considered to be the hardest type of drill bits available. This is because they are made of a cobalt alloy with a uniform concentration throughout the entire bit. 

This uniformity in the cobalt concentration makes the drill bits harder and more durable than other types of drill bits, such as black oxide or HSS. They can withstand more wear and tear and are better suited for drilling into harder materials.

Durability:

Cobalt drill bits are known for their superior hardness and strength, which makes them more durable than steel drill bits. They are specifically designed to withstand the demands of drilling on tough materials such as cast iron, stainless steel, and other hard metals. 

Black oxide drill bits, on the other hand, tend to lose their edge quickly when used on challenging materials. While they can be re-sharpened, the process is not as efficient as sharpening cobalt bits. 

In addition,  cobalt bits have a uniform concentration of cobalt throughout the bit, which allows them to be sharpened if the edge becomes worn or dull. Overall, cobalt bits are a more durable choice for drilling on hard materials.

Surface treatment:

Black oxide drill bits are treated with a black oxide coating that helps to protect them against rust and corrosion. Cobalt drill bits, on the other hand, are not treated with any special coating, but their cobalt steel construction makes them more resistant to wear and tear.

Performance:

Black oxide drill bits are suitable for drilling into a variety of materials, including wood, metal, and plastic. They are also good for drilling at high speeds. Cobalt drill bits, on the other hand, are best suited for drilling into harder materials, such as stainless steel and cast iron, and can withstand higher drilling temperatures.

Cost:

Cobalt drill bits are typically more expensive than black oxide drill bits, due to their cobalt steel construction and superior performance.

Black oxide drill bits are suitable for drilling into a variety of materials, while cobalt drill bits are best suited for drilling into harder materials. Cobalt drill bits are more heat-resistant and durable than black oxide drill bits and are more expensive.

Features and Specifications of Black Oxide and Cobalt Drill Bits

Durability and Versatility:

Black oxide drill bits are known for their tough exterior which is 2 times more durable than a regular drill bit, thus making them last longer by 50%. However, when it comes to overall durability, cobalt drill bits are considered to be the best option. 

They are made of a material that is much stronger than black oxide or titanium.

Black oxide drill bits are specially designed to quickly and efficiently drill through various types of wood, including hardwoods like oak and maple, as well as softer woods like pine. 

They are commonly used in woodworking projects for creating precise holes. On the other hand, cobalt bits are known for their ability to withstand high temperatures

Non-corrosive and Speed:

Cobalt drill bits are a type of drill bit that is made from a combination of high-speed steel and a small percentage of cobalt alloy, typically between 5-8%. This composition makes them highly resistant to rust and corrosion, making them popular among professionals in the building and metalworking industries. 

Additionally, cobalt drill bits are known for their fast drilling capabilities due to the presence of a black oxide coating that reduces friction while drilling.

Affordability and Re-sharpening:

Cobalt drill bits are more expensive than other types of drill bits, such as black oxide, but they are also more efficient and have a longer lifespan. 

They can also be re-sharpened using a drill bit sharpener, which makes them more cost-effective in the long run. Unlike titanium bits, cobalt bits do not require re-coating with oxide, making them more durable and reliable. 

The uniform concentration of cobalt in these bits also helps to increase their strength and longevity. Overall, while they may cost more upfront, cobalt drill bits are a wise investment for those who need to drill frequently or for heavy-duty projects.

Will both work the same?

While some may believe that using black oxide to hone your drill bits is not worth it, there are many uses for this product!

Most importantly, using black oxide as the abrasive material in your drilling process will give you very durable bits. This means you can use these drills for longer than normal without having to replace them!

It also helps prevent corrosion of the bit itself, which would reduce the effectiveness of the tool. If you are looking to save money by buying cheap tools, this information may be helpful to know!

What should I look for when buying either?

There is a major difference between cobalt drill bits and black oxide drill bits. The price!

Drill bit manufacturers may label their products as containing “black oxide” or “copper oxide,” but they are actually made of pure copper. It is the oxidized layer that contains the trace amounts of zinc and/or nickel that give them their color and hardness.

Copper is much more affordable than either zinc or nickel so it is cost-effective to buy cheap copper drills. This is why we see lots of low-priced drills that claim to be coated in black oxide. They are not!

We have spoken about the dangers of using low-quality drilling equipment before, and this is another example of it. These lower-price drills do not hold up well because they do not contain any of the expensive minerals that take time to form a protective coating.

These materials add to the expense of owning a high-quality drill, which is what you want if you plan to invest in mining equipment. We recommend staying within budget and looking for examples of good quality drills before going shopping.

Hopefully, you learned something here today by taking some time to compare both types of drill bits.

Are there any disadvantages to using either?

It is important to consider whether you will need new bits. Some companies will run out of their current stock, so it’s best to be aware of this before buying anything.

A lot of people use black oxide as their grinding medium because it lasts longer than cobalt drill bits. However, the black oxide can become thinner over time, which could cause problems in the future. If your pieces are still working well now, but you feel that they are starting to lose some strength, then it might be better to get a new bit.

You would do the same with steel drills – if they start to burn slightly more easily, it could mean that they are wearing down. It wouldn’t hurt an old drill too much, but it would eventually limit your productivity. So make sure you have enough for your next job!

Drill bit hardness also makes a difference. Most high-quality stainless steel drill bits are at least HRC 65-70 (hardness scale). An easy way to tell how hard a material is is to try rubbing it against another piece – the harder the material, the more friction is generated.

What should I do if I need to repair my drill?

If you run out of either black oxide bits or cobalt bits, there are many alternatives to buying new ones! You can always visit your local home improvement store or online shopping site to see what types of replacements they have.

Some alternative drill bits that may be useful in replacing lost bits are ceramic bits, silicon carbide bits, titanium alloy bits, and even plain old steel bits!

Any of these will work just as well as white metal bits but may be more expensive. It depends on how much you use your drill and whether or not you want to invest in better-quality bits.

FAQ’s

What drill bit will go through the steel?

High-speed steel (HSS) or cobalt drill bits are best for drilling through steel.

Can you sharpen cobalt drill bits?

Cobalt drill bits can be sharpened using a drill bit sharpener specifically designed for cobalt bits. However, it’s worth noting that they may not be able to be sharpened as many times as regular HSS drill bits, as cobalt is a harder material and can wear down the sharpening tool faster.

Which is better cobalt or carbide?

Cobalt drill bits are better for drilling harder materials, such as stainless steel and cast iron, while carbide bits are better for softer materials, such as wood and plastic.

Conclusion: 

I hope, In this article, you have decided to choose which one is better for you, both black oxide and cobalt drill bits have their own advantages and disadvantages. Black oxide drill bits are more economical and can be sharpened easily. However, they may not be as durable as cobalt drill bits, which are more expensive but last longer and can handle harder materials such as stainless steel and cast iron. When choosing between the two, it’s important to consider the specific project and material you will be drilling. If cost is a major concern and you are drilling soft materials, the black oxide may be the better choice.

Thank You!