What are Cobalt Drill Bits Used For

When your standard drill bit just won't cut it, it's time to upgrade. Cobalt drill bits are the go-to tool for handling the toughest materials, from hardened steel to cast iron. They are particularly good at cutting strong metals such as stainless steel and cast iron; apart from this, they can also be used on soft materials.

Find out what makes cobalt drill bits so powerful and how they can save you time and money on your next project.

What is a Cobalt Drill Bit?

A cobalt drill bit is a type of metal drill bit made from a steel alloy that contains 5 to 8% cobalt. This small percentage of cobalt is the key to the bit's superior performance, as it creates a stronger, more heat-resistant tool. While they may look similar to standard high-speed steel (HSS) bits, their unique composition allows them to handle much more demanding tasks without losing their edge.

Why Choose a Cobalt Drill Bit?

The benefits of choosing a cobalt drill bit over other types of bits are significant, especially for drilling hard materials.

• Excellent Durability and Strength: The 5-8% cobalt element makes the bit much harder and more wear-resistant than standard HSS.
• High Heat Resistance: Cobalt is highly effective at withstanding the extreme temperatures generated from drilling hard metals. This prevents the bit from dulling or melting during use.
• Hardness Throughout the Bit: Unlike some coated bits, a cobalt bit's hardness is consistent throughout the material. This means it can be sharpened as needed without losing its cutting ability, extending its lifespan significantly.

What are Cobalt Drill Bits Used For?

Cobalt drill bits are made for drilling into tough materials. They are a top choice for professionals and DIYers who need to drill through:

• Hardened steel
• Stainless steel
• Tool steel
• Cast iron
• Aluminum alloys

While they can technically be used on softer materials, they are not ideal for general use on wood or plastic, as dedicated wood and plastic bits are better suited for those tasks.

How to Use a Cobalt Drill Bit Effectively?

Using a cobalt drill bit correctly is essential for success and for extending the life of your bit. The key is to manage heat, as excessive heat can quickly dull or even destroy the cutting edge.

• Use a Lubricant or Cutting Fluid: For drilling hard metals like stainless steel, always use a lubricant or cutting fluid. This reduces friction, dissipates heat, and helps clear metal chips, allowing for a cleaner and faster cut.
• Adjust Your RPMs: Unlike drilling wood, drilling hard metals requires a slower speed. Use a drill press or a variable-speed drill and set the revolutions per minute (RPM) to a low setting. A slower speed generates less heat and allows the bit to bite into the metal properly.
• Apply firm, consistent pressure. A common mistake is to let the bit "ride" on the surface, which generates heat without cutting, leading to rapid dulling. Consistent pressure allows the bit to cut efficiently and keeps it from overheating.
• Wear Safety Gear: Always use safety glasses to protect your eyes from flying metal chips.

Conclusion

If you're frequently drilling into metal, cobalt drill bits are a worthwhile investment, even though they typically cost more than standard bits. Their superior strength, heat resistance, and ability to be resharpened make them a wise long-term investment. If you need to tackle a tough job, a cobalt drill bit will provide the durability and performance you need to get the job done right.

For all your drilling needs, check out drill bit sets, a collection of various drill bits from Benchmark Abrasives, designed to complete your drilling tasks with the best results.

Read More: Essential tools for metalworking