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Cobalt Drill Bits

Best Cobalt Drill Bits in 2023

The Adiseal Ultimate cobalt metal drill bit stands out as the superior choice among metal drill bits. It showcases exceptional strength and speed, outperforming all other available options. In our tests, it drilled more holes than any competing metal drill bits, surpassing even the top brands including Dewalt, Bosch, Milwaukee, and Bosch.

Best cobalt drill bit for metal test results chart.

Best cobalt metal drill bit durability test results

10mm metal cobalt drill bitTotal number of holes drilled (in 6mm stainless steel)
Adiseal Ultimate cobalt135 holes
Milwaukee cobalt red75 holes
DeWalt Extreme cobalt39 holes
Bosch cobalt15 holes
Makita cobalt12 holes
Cobalt drill bit durability test results

Impressively, Adiseal Ultimate drilled more holes than the best cobalt bits from the top 3 worlds biggest brands combined. (Milwaukee cobalt red) 75 + (DeWalt Extreme cobalt) 39 + (Bosch cobalt) 15 = 129 holes vs Adiseal Ultimate 135 holes .

Adiseal Ultimate drilled 9 times the number of holes than the best cobalt bit from Bosch & over 3 times the number of holes than the best cobalt bit from DeWalt.

Best metal drill bit speed test results

In addition to drilling the highest number of holes among metal drill bits, the Adiseal Ultimate also boasts the fastest drilling speed. In the same test mentioned earlier, we measured the time taken to drill each hole, recording the average time for the first 10 holes.

10mm metal cobalt drill bitAverage time to drill each hole (in 6mm stainless steel) for first 10 holes
Adiseal Ultimate cobalt31.7 seconds
DeWalt Extreme cobalt38.5 seconds
Milwaukee cobalt55.8 seconds
Makita cobalt69.9 seconds
Bosch cobalt132.4 seconds
Metal cobalt drill bit speed test results

Adiseal Ultimate was over 4 times faster the best cobalt bit from Bosch.

By drilling faster & more holes than any other bit, Adiseal Ultimate cobalt drill bit saves money, time, tools & energy.

Please note, these are our test results from internal testing. We recorded a video of each hole being drilled. These videos are available on request for your test accuracy verification purposes.

best cobalt metal drill bit

Cobalt metal drill bit test

We performed tests using a Scheppach DP60 drill press to determine the best metal drill bit for creating 10mm holes in 6mm thick stainless steel (SUS304). The drill press consistently maintained a speed of 400 rpm for all tested bits, including 10mm metal cobalt drill bits from renowned brands like Milwaukee Cobalt Red, DeWalt Extreme, Bosch Cobalt, and Makita. To ensure uniformity, a 5kg weight was suspended on the drill press arm during each hole’s drilling to maintain consistent force and RPM. Notably, we conducted durability tests without lubricants, coolants, or cutting oils, though these substances can aid in reducing the bit’s temperature and extending its lifespan. The drilling processes were recorded and timed using video timestamps. Following these tests, the Adiseal Ultimate drill bit emerged as the top performer, excelling in both the number of holes drilled and the time taken for each hole.

Drill bit for metal test results chart

It’s essential to highlight that non-cobalt drill bits, such as HSS bits (high-speed steel), including Milwaukee Thunderweb and Bosch PointTeq, were tested but were excluded from the chart to ensure fairness. Notably, Bosch PointTeq couldn’t drill any holes into the 6mm thick stainless steel SUS304 during the testing.

Kindly note, these results stem from our internal testing. We have video recordings of each hole drilled, available upon request for your verification to ensure test accuracy.


Saves money

In the long run, inexpensive drill bits might become more costly if they wear out faster and drill fewer holes compared to durable ones. Determine the cost per hole by dividing the bit’s price by the total holes drilled. Cheaper bits could potentially have a higher cost per hole than more resilient options. Notably, in our test, Bosch PointTeQ’s non-cobalt bit couldn’t drill any holes, whereas the Adiseal Ultimate metal drill bit successfully drilled 135 holes.

Example of cost per hole

To compare costs, let’s consider drilling 10 holes in 6mm stainless steel with the Adiseal Ultimate and Bosch cobalt drill bits.

Adiseal Ultimate 10mm metal drill bit price: £10.14
Cost per hole (£10.14 / 135 holes): £0.076666
Cost to drill 10 holes: £0.77

Bosch cobalt metal drill bit price: £8.31
Cost per hole (£8.31 / 15 holes): £0.554
Cost to drill 10 holes: £5.54

Based on cost per hole, Adiseal is more cost-effective. Further savings can be observed as detailed below.

Saves time

A drill bit that drills faster not only decreases the cost per hole but also lowers labor expenses. The reduced drilling time per hole leads to additional cost savings overall.

Example of saving money on labour cost

To showcase potential labour cost savings, let’s examine the time and effort needed to drill 10 holes in 6mm stainless steel using the Adiseal Ultimate and Bosch cobalt bits.

Assuming a construction contractor pays £20 per hour for a tradesperson’s work, it amounts to £0.00555 per second.

Adiseal Ultimate: 317 seconds to drill 10 holes.
Labour cost: £1.76

Bosch cobalt: 1324 seconds to drill 10 holes.
Labour cost: £7.36

Adding these labour costs to the drilling costs above, total cost to drill 10 holes is:
Adiseal Ultimate: £2.53
Bosch cobalt: £12.90

In reality, further savings arise from extended tool lifespan, decreased energy consumption per hole, and fewer trips required to purchase replacement bits.

Saves tools

Quicker drilling extends the tool’s lifespan by minimizing usage. Slower drilling bits prolong runtime, potentially leading to faster wear. Tools with extended lifespans can result in additional cost savings.

Saves energy

Quicker drilling decreases tool runtime, conserving energy and generating additional savings beyond those mentioned. The reduced energy required for drilling each hole also positions the Adiseal Ultimate as the most environmentally friendly metal drill bit.

Other benefits

Adiseal Ultimate cobalt drill bits, with their sharp cutting edge, eliminate the need for pilot holes, preventing sliding and wandering. Additionally, they create larger pieces, minimizing the necessity to clear multiple small chips post-drilling, thus delivering cleaner cut holes compared to alternative bits.

How to use a cobalt metal drill bit

How to drill with a cobalt metal drill bit

  1. Safety First

    Put on safety goggles to protect your eyes from debris.

  2. Setup

    Secure the metal piece firmly in place using clamps or a vise to prevent movement during drilling.

  3. Marking

    Use a center punch or awl to create a starting point on the metal surface. This helps guide the drill bit and prevents it from slipping.

  4. Drilling Angle

    Hold the drill perpendicular to the metal surface to ensure a straight and precise hole.

  5. Drilling Speed

    Start drilling at a slow speed to prevent overheating and allow the bit to grip the metal surface. Once the bit has established a groove, gradually increase the drill speed.

  6. Lubrication

    Consider using a lubricant or cutting oil to reduce friction and heat buildup during drilling. This helps extend the lifespan of the drill bit.

  7. Steady Pressure

    Apply constant and steady pressure while drilling to maintain control and prevent the bit from wandering.

  8. Cooling Periods

    Periodically stop drilling to let the bit and metal cool down if they become too hot. This prevents damage to both the bit and the metal surface.

  9. Clean-up

    Once drilling is complete, remove the drill bit slowly while the drill is still running to clear any remaining metal debris. Clean the drilled hole and the metal surface.

Be cautious when handling the drilled material or the drill bit afterward, as they might still be very hot. Hot metal can cause burns, so either let them cool before touching with bare hands or use suitable heat-resistant gloves.

Exercise caution when handling the removed chips as they can be extremely sharp and easily cause cuts. If you need to handle them, it’s advisable to wear gloves for protection.


What materials can Adiseal Ultimate cobalt metal drill bit drill into?

Adiseal Ultimate heavy duty cobalt metal drill bit is also suitable at drilling many other materials including:

  • Stainless steel
  • Hardened steel
  • Metal
  • Aluminum
  • Bronze
  • Brass
  • Copper
  • Cast iron
  • Plain carbon steel
  • Wood
  • Plastic
  • Fiberglass
  • Plus many other materials

What sizes are Adiseal Ultimate cobalt metal drill bits available in?

Adiseal Ultimate cobalt metal drill it is currently available in the following sizes:

Where to buy cobalt drill bits for metal

In the UK to buy cobalt drill bit for metal, please contact us for details of your local stockist. For other countries, please visit www.guglue.com

Adiseal Ultimate Masonry & Multi Material Drill Bit

In their attempt to make available the best drill bits, also in the Adiseal Ultimate range is the fastest no hammer masonry drill bit & multi material drill bit. It can drill faster than any other drill bit when drilling without hammer function on the drill. This gives it numerous advantages over hammer drills. It will drill into brick, drill concrete, wood and many other building materials. This carbide bit has been shown to be the best masonry drill bit with a hex shank.

Frequently asked questions about metal drill bits

What is a cobalt drill bit used for?

Cobalt drill bits are used for drilling tough materials such as stainless steel, cast iron, and high-strength alloys. They’re designed with a blend of cobalt and high-speed steel for durability and heat resistance, ideal for high-temperature drilling in these materials. Their enhanced strength makes them effective where regular bits might struggle or wear out.

Are cobalt drill bits the strongest?

Cobalt drill bits are some of the strongest options for tough materials like stainless steel. They’re highly durable and heat-resistant due to their blend of cobalt and high-speed steel. While they’re quite strong, there might be specialized drill bits with unique compositions designed for specific purposes that are also exceptionally robust.

What is the difference between 5% and 8% cobalt drill?

The cobalt percentage in drill bits indicates the cobalt content in the high-speed steel (HSS) used.
5% Cobalt Bits: These contain around 5% cobalt, offering decent durability for general drilling in materials like steel, aluminum, and wood. They might not handle extreme heat as well as higher cobalt content bits.
8% Cobalt Bits: With roughly 8% cobalt, these bits are more heat-resistant and durable. They’re suitable for harder materials like stainless steel and cast iron, handling higher drilling temperatures effectively.
Higher cobalt content generally improves heat resistance and durability, especially for challenging drilling tasks.

Can I use cobalt drill bits on wood?

While cobalt drill bits can be used on wood, they’re primarily designed for tough materials like stainless steel and cast iron. For woodworking, standard high-speed steel (HSS) or brad point drill bits are more suitable, offering efficient and precise drilling in wood. Cobalt bits might work on wood, but they might not provide the same precision or efficiency as bits designed specifically for woodworking tasks.

Will a cobalt bit drill stainless steel?

Yes, cobalt drill bits are specifically designed to drill through tough materials like stainless steel. Their construction, which often includes a mix of cobalt and high-speed steel (HSS), provides enhanced durability and heat resistance, making them well-suited for drilling into stainless steel and other hard alloys. These bits are more effective in handling the high temperatures generated during drilling into tough materials, making them suitable for such applications.

Suhail Matadar has extensive experience in the construction industry as an electrician, involved in installing, inspecting, and testing electrical systems in various projects. He excelled in sales, working for a major UK wholesaler, selling construction products to professionals and the DIY market. Suhail's background includes working at a leading home emergency repair company dealing with trades people. With a BEng (Hons) degree in Electronic Engineering, Suhail has worked with PLCs in the nuclear fuel manufacturing industry. During his studies, he gained practical experience at a chemical manufacturing company known for producing award-winning cleaning, hygiene, and livestock protection products for over a century. Currently, Suhail runs a global business specialising in supplying, researching, testing, and distributing chemical construction products like adhesives and sealants.