Black oxide drill bits are black in color, and it is made with HSS by coating a magnetite (Fe3O4) layer. Due to its hardness and heat resistance, it can use to drill a wide range of materials such as steel, copper, wood, aluminum, etc. Black oxide drill bits have a 50% service life than regular HSS drill bits.
When we are going to select a drill bit, we should know workpiece hardness, drilling depth, drill bit hardness, RPM, thrust, and many more. In this guide, you can learn everything about black oxide drill bits in detail. So let’s keep reading on.
What are Black Oxide Drill Bits Used for?
Black oxide drill bits are coated drill bits. These are usually capable of drilling or piercing many materials. That is a multifunctional bit type compared to other bits. These drill bits can be used for wood, metal as well as plastic.
Therefore black oxide drill bits are suitable for work on;
- Steel,
- Copper,
- Aluminum,
- Brass,
- Oak,
- Maple,
- Pine
- MDF,
- PVC,
- Polycarbonate,
- Acrylic,
- ABS,
- Nylon, and composite materials.
Read More About – Are Black Oxide Drill Bits Good for Metal? [Ultimate Guide]
Can I Resharpen a Black Oxide Drill Bit?
Black oxide is a coating. When you resharpen it, its layer will damage, and performance will reduce. But some performance will remain if you do not damage the outer layer of the drill bit.
If re-sharpened, the outer coating will scratch, and the bit will become unusable because this outer coater is made by the chemical process. If it has not been used externally coat, a person may think that it can be used by sharpening again. But external coating has increased the efficiency of these drill bits. Under that,
- Reduces friction between bits and materials.
- Performs more accurate drillings.
- Controls the temperature rise of the bits during the drilling process.
Once you’ve noticed that the drill bit is blunt or broken, you need to choose which tool to use according to the size to be sharpened.
The dull drill bit must keep at a 60o angle to the sharpening tool. Then has to cut the landing and the chisel and has to sharpen the landing of the drill bit.
How to Resharpen a Black Oxide Drill Bit?
You can follow these resharpening steps when you are going to resharpen it.
- Examine the dull bit
- Pick your tool of choice
- Hold the bit correctly
- Cut the landing
- Cut the chisel
- Shape the landing
- Rotate the bit
- Repeat
Durability of Black Oxide Drill Bits
Black oxide drill bits are also more durable than HSS drill bits. It is approximately 50% (as mentioned in tables no one and two above). We also find cases where black oxide drill bits are used for several years. Manufactured from black oxide rust resistance, non-corrosive material, it increases the durability of drill bits and improves the practical performance of the bits.
These drill bits can be re-sharpened, especially during long-term drilling operations, as these bits can be re-sharpened.
Black oxide drill bits cannot be used for as long as cobalt bits. Black oxide bits lose their edge when used on hard materials. Therefore black oxide drill bits are not suitable for more rigid materials.
Are Black Oxide Drill Bits Better than Titanium Drill Bits?
Generally, black oxide drill bits are not good as titanium drill bits. Black oxide drill bits are cheap, it is good for starters, and it can be resharpened easily, but it is not able to use for harder materials. As well as black oxide drill bits are not high heat resistant as titanium drill bits. More than that, black oxide drill bits have a short service life considering the titanium drill bits.
Black oxide and titanium are both considered as finishing materials. The purpose of the finishing material is to reduce friction and improve thermal stability and durability. Under this circumstance, titanium drill bits are harder and have higher performance than black oxide drill bits.
Black Oxide vs. Titanium Drill Bit Comparison
Black oxide and titanium are applied on the drill bits as a coating. After the coating is applied, it provides additional physical characteristics to the drill bit. Its hardness, durability, and many more factors have improved. However, titanium is better than black oxide coating. Mainly Titanium coatings are 3 types such as TiN coating , TiCN coating, and TiAlN coating.
| Characteristics | Titanium drill bits | Black oxide drill bits |
| Hardness | Harder than black oxide drill bits | Hardness enough to drill more materials |
| Durability | Durable than 3 to 6 times than HSS | 50% more durable than HSS |
| Rust resistance | Yes | Yes |
| Drilling speed | Fast | Fast |
| Re-Sharpenable | No | Yes |
| Price | Fairley expensive | Cheapest |
| Suitable for | Professionals only can use | Woodworkers, amateurs, |
| Material can be drilled | Wood, metals | Wood, metals, and plastic |
In conclusion, Titanium drill bits are more suitable for drilling metals when comparing these two bits.
But with the ability to sharpen again and use many materials at low cost without fear, even for beginners, black oxide drill bits are practically more effective for everyday tasks.
Black Oxide vs Cobalt Drill Bits
While black oxide is a finished material, and cobalt is the base material for the drill bits. Cobalt drill bits are harder and tough than black oxide drill bits. Hence cobalt drill bits are used to drill harder metals such as cast iron and hardened steel. But black oxide drill bits do not have this kind of performance. We can compare black oxide and cobalt drill bits as below.
| Characteristics | Cobalt Drill Bits | Black Oxide Drill Bits |
| Hardness | Hardest | Hardness enough to drill more materials |
| Durability | Highest durability | 50% more durable than HSS |
| Rust resistance | Yes | Yes |
| Drilling speed | Fast | Intermediate |
| Re-Sharpenable | Yes | Yes |
| Price | Expensive | Cheapest |
| Suitable for | Wood, metals, and plastic | Suitable for Professionals |
| Material can be drilled | Hard metals | Wood, soft metals, and plastic |
When considering black oxide vs cobalt drill bits, cobalt drill bits are more suitable for drilling metals when comparing these two bits, but it is cheaper to use black oxide drill bits that work for cobalt bits to drill a lighter material.
Black Oxide vs Gold Oxide Drill Bits
Gold (III) Oxide is an inorganic compound with the formula Au2O3. Since it is the least reactive metal in the environment, gold is not found in nature as an oxide. It is artificially created by man. Gold oxide is a chemical compound that is water-insoluble and heat-decomposable.
Both of these features may have contributed to the creation of a better bit of HSS bits. Gold oxide powder is brownish-black colored powder. Therefore the black oxide drill bits have also the same color.
Both black oxide and gold oxide coatings reduce friction between the bit and the material. Makes more accurate drilling. Controls the temperature rise of the bits during the drilling process. The gold oxide drill bits also provide extra speed and durability to typical work drill applications in wood, metal, and plastic.
Black Oxide Drill Bits and Their Material Properties
First of all we should study the manufactured material of the black oxide drill bits because all of the characteristics depend on the material properties.
Manufacturing
The manufacturer heats the HSS drill bits to a high temperature of about 950-celsius degrees and releases these bits are resisted corrosion and decomposition. Black oxide bits are up to 50% longer than normal HSS bits.
Black oxide bits can be described as the best general-purpose drill bits you can buy because they have much durability and can work at very good speeds. As well as black oxide drill bits have a long service life than HSS drill bits
Coating Process
The HSS drill bit has faced the black oxide coating process. This coating method can be applied to steel, cast iron, aluminum, copper, brass, zinc, bronze, and other non-corrosive materials. Under this process, this type of coating directly lays on the material with a chemical conversion rather than applying it like an electroplating process.
Due to this coating, we can identify drill bits with others.
A black oxide solution includes salts that act as an oxidizer. That solution reacts with the iron in the steel by using the salts of the solution and creates a coating over the surface.
This coating is important to reduce friction and corrosion between the faces of the bit and material and thermal resistance. This advancement in technology makes it easier to use without overheating the drill bit.
Is It Worth Using a Black Oxide Drill Bit?
If you have to do a long period of drilling work or a hard material drilling process, unconditionally, you have to use the cobalt drill bits or carbide drill bits for that because black drill bits tend to lose their edges very easily than cobalt drill bits and carbide drill bits.
Black oxide drill bits can be re-sharpened by using a drill bit sharpener, but a skilled person can use a grinding disc and re-sharper by hand. It is the cheapest drill bit like an HSS drill bit.
In Conclusion
The final conclusion is that black oxide drill bits are most suitable and worth regular usage, but they are not good for professional and continued use.
- Reasonably priced,
- Durable (non-corrosive and can be re-sharpened),
- 50% more durable than regular HSS drill bits,
- It can be used for various purposes,
- Making them the best all-purpose bits.
At first, you have to determine the metal or material type required to drill. Among both of those, cobalt drill bits are the most effective and best drill bit. Although black oxide drill bits are worth using for constructions that are done with very low financial conditions.
