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What Is A Drill Bit Made Of?

Drill bits can be of hundreds of different types based on the construction, orientation, and application. A professional plumber uses different types of drill bits for his everyday drills. If you are a homeowner, you may also have experienced drill bits of varying types. Have you ever thought about what a drill bit is made of? In this article, we will try to find the answer to this question.

Materials That Are Used To Manufacture Drill Bits

The material to produce drill bits should be hard enough to withstand powerful operations. Steel is a preferred alloy because it is hard and comparatively less brittle. It is an alloy that is composed of different metals to having a different composition.


High carbon steel- This carbon alloy has a carbon content of more than 0.3%. Drill bits made of high carbon steel are durable and hard. These are used to cut soft to hard objects such as woods and metals. Drill bits made of high carbon steel have tempering treatment. They can lose the tempering if overheated.

Low carbon steel – Low or mid carbon steel contains carbon ranging from 0.05 to 0.3%. The advantage of using low carbon steel as a material of drill bit is that it is cheap. But the tensile strength is not as good as the high carbon steel.  Drill bits made of low carbon steel are used for soft objects such as wood. If you want to enhance the lifespan, then you should sharpen the drill bits made of low carbon steel.

High-speed steel – This is also a kind of steel that is harder than high carbon steel. High-speed steel is higher heat resistant. When you work at high speed, then it may produce a high temperature. Drill bits made of high-speed steel are designed to withstand these kinds of operations. Concrete, metal, and hard woods are materials that need special kinds of drill bits that are made of this kind of material. Read our article to know about the difference between concrete and wood drill bits.

Material other than steel

Tungsten carbide – carbides are extremely hard materials. The problem with carbide is that it is brittle. Therefore, tungsten carbide is used to prepare drill bits in a limited way. Tips of the drill bits and small pieces of bits are produced with tungsten carbide. These small drill tips are used to make holes with very small diameters.

Polycrystalline diamond – It is the hardest material on earth. Diamond crystalline is used on a suitable metal alloy to give a super hard structure. Therefore, drill bits that are made of this compound are highly resistant to wear.

Coating material

The coating is necessary to give the drill bits a smooth surface so that it gets lubricity. On top of that, it protects the surface of the drill bits from corrosion. It is important to enhance the life of the drill bits.

Black oxide – It is one of the most inexpensive black coatings to provide the necessary quality such as lubricity, heat resistance, and so on.

Diamond powder – Sometimes you need an abrasive surface for cutting hard and sophisticated materials such as tiles, stones, glass, and so on. Due to the friction during operation, a lot of heat is generated. Therefore, we often see manual water cooling to prevent the drill bit from damage.  

Titanium alloy – Different types of Titanium alloy is used for coating the drill bits. Titanium nitride is a common alloy for coating high-speed steel. It enhances the cutting life of the drill bits. Even if you sharpen it, it still provides you with improved cutting experience. Apart from this, Titanium aluminum nitride and titanium carbon nitride are also common titanium alloys that are widely used during the coating of drill bits.

Other coating material – Zirconium alloy is also used as a coating material for drill bits. But a few selective brands use it. Besides, chromium alloy is also common as a coating material for the drill bits.

Bottom line

The material of the drill bits consists of the main construction material and the surface coating. Both are important for longevity and performance. Before purchasing drill bits for a specific project, the construction material should be checked. Wrongly selected one may get damaged just after using a few times. The drill bit should be chosen as per the type of object that you work with.