Titanium drill bits are considered as a coating of the drill bit. When the drill bit is made with HSS, Cobalt, or any metal, Titanium is used to coat the drill bit in order to improve some characteristics. Pure Titanium is not applied to the drill bit. Titanium is mixed with Aluminum, Nitrogen, and Carbon and then it is applied around the drill bit. The most applied coatings are TiN, TiCN, and TiAlN.
When the coating is applied around the drill bit, its hardness, durability, corrosion resistance, and thermal resistance are improved. That is a great opportunity to use drill bits in a wide range. But when the coating is removed, its improvements are reduced.
Titanium drill bits are widely used for general-purpose drilling on materials such as magnesium, wood, aluminum, steel, and iron and last longer than standard metal drill bits
Colors and Materials for Titanium Drill Bits
You can find titanium drill bits in three types. Each type has a different color. The following table represents the colors of each category.
|TiN (Titanium Nitride)||Bright Gold|
|TiCN (Titanium Carbonitride)||Blue/ grey|
|TiALN (Aluminum Nitride)||Violet|
➤ Materials used in Titanium drill bits
Titanium drill bits are not completely designed with titanium. They are made with high-speed steel, including a thin titanium nitride coating, using a method similar to electroplating. Sometimes cobalt drill bits also used as base material of the drill bit.
|TiN Drill Bits||Carbide High-speed steel powder high-speed steel titanium Nitride|
|TiCN Drill Bits||Carbide High-speed steel powder High-speed steel titanium Carbonitride|
|TiALN Drill Bits||Carbide High-speed steel powder High-speed steel TitaniumAluminumNitride.|
Characteristics of Titanium Drill Bits
Titanium drill bits can mainly be classified into three types according to their coating. The following table presents the most crucial characteristics of the three major titanium coatings.
|Titanium Nitride (TiN):||➤ Widely used entry-level coating. Widely used with router bits, countersunk bits, etc. |
➤ Has a microhardness of between 2000 to 2500 HVM
|TiCN (Titanium Carbonitride)||➤ Performs better than the normal TiN coating. |
➤ Strong and has a much longer lifespan.
➤ Has a nano-hardness up to about 32 GPA.
➤ Best for drilling into medium to hard metals and softer materials.
➤ Withstand up to about 400°C temperature.
|TiALN (Aluminum Nitride)||➤ An universal applicable coating. Better than TiN and TiCN. Expensive compared to TiN, and TiCN.|
➤ Performs well in high-speed cutting applications. Increased productivity.
➤ Increase drill bit lifespan by up to 10x.
➤ Withstand temperatures up to 800°C.
➤ Can not drill through aluminum due to the increased aluminum content in the coating.
➤ Widely used on drill bits for cast iron and tough steels.
What Materials Can Be Drilled Using Titanium Drill Bits?
As titanium is harder than tool steel, drill bits have the ability to bore holes where regular drill bits cannot such as hard steel alloy and extremely hard alloys of stainless steel. The followings are the materials best to drill through Titanium drill bits
- Aluminium (only Tin and TiCN coats)
- Other Soft Metals
- Abrasive Plastics
- Hard rubber
Can You Sharpen Titanium Drill Bits?
Titanium drill bits are high-speed steel coated with a titanium formulation. So, once the coating is gone over time, even though you re-sharpen them, it will not show its best performance as the bit loses much of its heat resistance.
Therefore, rather than recoating them or re-sharpening it is always recommended to replace them with new ones. You should never try to sharpen the titanium drill bits before they get unusable. Even when the coating is gone they will still perform better than standard bits if the titanium coating in the flute and sides is still there.
What Are The Problems Of Titanium Drill Bits?
The main drawback of titanium drill bits is once the coating wears off, you can not receive the maximum performance of the bit. Even if you sharpen it nothing will change.
It is extremely difficult to sharpen these drill bits due to the extreme hardness of the drill bit.
You can not use titanium drill bits for hard abrasive metals such as cast iron as they can damage the coating.
Can You Use Titanium Drill Bits On Stainless Steel?
Stainless steel is an incredibly hard material made with durable construction like high-speed steel, titanium nitride, and cobalt. Due to this reason, Low-carbon steel bits are not an ideal choice for stainless steel. Subsequently, when choosing drill bits for stainless steel, it is recommended to go for a harder bit.
TiN-coated drill bits are used for drilling stainless steel as titanium coating performs well against friction and is strong enough to drill through hard materials like stainless steel. The included Titanium Nitride reduces friction and lowers the heat that hardens the material.