So cobalt is added to HSS during production. Often, these drills are considered disposable.Ĭobalt: These drill bits are not coated, but are formed as an alloy. Resharpening is possible, though the coating will eventually wear through, leaving only the HSS core. Buy from recognized brands to avoid disappointment.Ĭoncerns with coatings: The main drawback with tungsten carbide, black oxide, and titanium is that each is a coating. However, cheap sets sold as metalworking drill bits might have gold plating but don’t actually contain any titanium nitride. Titanium drill bits can drill both non-ferrous and ferrous metals (steel and cast iron).Ī note of caution: Titanium drill bits are often gold in color. Titanium also reduces friction between the drill bit and the material being drilled, so it offers good heat dissipation - and, since overheating is a major cause of wear, greater durability.

Like carbide and black oxide, it increases the drill bit’s hardness.

It is technically a ceramic, rather than a metal. Titanium (or TiN, titanium nitride): This is another form of coating applied to a HSS drill bit. Black oxide drills are a good general-purpose choice, capable of efficient drilling of a wide variety of materials, including non-ferrous metals. The resulting drill bit can be 50% harder than HSS. Carbide drill bits can produce acceptable performance in non-ferrous metals, but while popular for masonry drills, the material is not often used for metalworking drill bits.īlack oxide: This coating is created by a chemical reaction between high-speed steel and sodium at high temperatures. Tungsten carbide (often just called carbide): This is a tungsten-and-carbon composite fused to a HSS core to increase drill bit hardness. However, HSS is softer than other drill bits for metal and wears quickly. HSS is great for drilling wood and plastic, and it can also drill through non-ferrous metals (those that don’t contain iron) such as aluminum and brass. Several of the other types of metalworking drill bits also have HSS at their core. As a result, it is used for all kinds of cutting tools. High-speed steel (HSS): The most common drill bit material, it is relatively hard, affordable, and easy to manufacture in different forms. Key metalworking drill bit set features Metalworking drill bit materials and coatings Allow time for the drill bit to cool before trying to change it. Drilling metal creates a great deal of heat.

Drill bit for metal