Have you ever tried drilling through hardened steel? It can be a daunting task, even for the most experienced DIYers and professionals. But fear not, because in this article, I’m going to share with you some essential tips and techniques that will make drilling through hardened steel a breeze.

Whether you’re working on a home improvement project or a challenging industrial task, drilling hardened steel requires a different approach than drilling softer materials. It demands the right tools, the right techniques, and a whole lot of precision. So, are you ready to unlock the secrets of drilling hardened steel like a pro?

Key Takeaways:

  • Understanding the properties of hardened steel is crucial before attempting to drill through it.
  • Choosing the right drill bits specifically designed for hardened steel is essential for success.
  • Properly preparing the workpiece, lubricating the drill bits, and applying the right pressure and speed can make the drilling process smoother.
  • Using cooling techniques and effectively managing chip removal contribute to a more efficient drilling experience.
  • Always prioritize safety by wearing protective gear and following workspace precautions when drilling hardened steel.

Understanding Hardened Steel

Before we dive into the drilling techniques, it’s important to understand what hardened steel is and its unique properties. Hardened steel refers to steel that has undergone a heat treatment process to increase its hardness and durability. This process involves heating the steel to a high temperature and then cooling it rapidly, which creates a strong crystalline structure.

Drilling into hardened steel can be a challenging task due to its high strength and resistance. The hardness of hardened steel is measured on the Rockwell scale, with higher numbers indicating greater hardness. Common hardened steel materials include hardened steel plates and toughened steel.

When drilling hardened steel, it is crucial to use the appropriate drilling techniques and tools to prevent damage to the steel and ensure a successful drilling process. Failure to drill hardened steel properly can result in broken drill bits, decreased drilling efficiency, and potential safety hazards.

Characteristics of Hardened Steel

Hardened steel possesses several distinct characteristics that set it apart from regular steel:

  • Exceptional hardness: Hardened steel is extremely tough and has a high resistance to wear and abrasion.
  • Increased strength: The heat treatment process significantly enhances the strength of hardened steel, making it ideal for applications requiring durability.
  • Reduced ductility: Hardened steel has reduced ductility, meaning it is less prone to deformation under stress.
  • High tensile strength: Hardened steel can withstand higher levels of tension without breaking or deforming.
  • Enhanced corrosion resistance: The heat treatment process improves the steel’s resistance to corrosion, increasing its lifespan.

Drilling Hardened Steel: Key Considerations

When drilling into hardened steel, there are a few key considerations to keep in mind:

  1. Use high-quality drill bits specifically designed for drilling hardened steel. These bits are often made from materials such as cobalt or carbide, which provide greater strength and heat resistance.
  2. Apply steady but controlled pressure while drilling to avoid overheating the drill bit or causing it to wander off course.
  3. Use cutting fluids or lubricants to reduce friction and heat buildup during the drilling process.
  4. Securely clamp the workpiece to prevent movement and ensure stability during drilling.
  5. Regularly inspect the drill bit for signs of wear or damage, and replace it if necessary.

By understanding the unique properties of hardened steel and implementing the appropriate drilling techniques, you can successfully drill through toughened steel and achieve accurate, precise results. In the next section, we will explore how to choose the right drill bits for drilling hardened steel.

Choosing the Right Drill Bits

The success of drilling hardened steel largely depends on using the right drill bits. The hardness of the steel requires drill bits that are specifically designed to handle the task effectively. Here, I will explore the different types of drill bits available and provide recommendations for the best ones to use when working with hardened steel.

Types of Drill Bits for Hardened Steel

When it comes to drilling hardened steel, there are three main types of drill bits that are known for their effectiveness:

  1. Cobalt Drill Bits: Cobalt drill bits are made from a solid cobalt alloy, which allows them to withstand the high heat and abrasion that drilling hardened steel can generate. These bits have a high red hardness, making them ideal for tough materials like hardened steel. They are also known for maintaining their sharpness and durability over time.
  2. Carbide Drill Bits: Carbide drill bits are another excellent option for drilling hardened steel. These bits are made from a tough carbide material that is combined with cobalt for enhanced strength and heat resistance. Carbide drill bits feature a unique tip design that allows for precise drilling and reduced heat generation.
  3. High-Speed Steel (HSS) Drill Bits: While not as hard as cobalt or carbide drill bits, high-speed steel (HSS) bits can still be effective for drilling through hardened steel. HSS drill bits are made from a hardened steel alloy and are more affordable compared to cobalt or carbide bits. They can handle the heat generated by drilling hardened steel to a certain extent, but may not be as durable in the long run.

It’s important to note that regardless of the type of drill bit you choose, using a drill press or a sturdy handheld drill with a variable speed setting is highly recommended to ensure precise control and prevent bit breakage.

Best Drill Bits for Hardened Steel

Based on my research and personal experience, here are some top recommendations for drill bits that consistently deliver excellent results when drilling hardened steel:

Drill Bit Brand Drill Bit Type Features
Bosch Cobalt Drill Bits Durable cobalt construction, optimized geometry for precise drilling
DeWalt Carbide Drill Bits Carbide tips for extended bit life, pilot point design for reduced bit walking
Irwin Tools High-Speed Steel (HSS) Drill Bits Made from M42 cobalt-enhanced high-speed steel for improved performance

These brands have a strong reputation for producing high-quality drill bits that can tackle hardened steel with ease.

Remember, when working with hardened steel, it’s important to use proper drilling techniques, such as applying consistent pressure and using lubrication to reduce friction and heat. With the right drill bits and a bit of practice, you’ll be able to drill through hardened steel like a pro!

Preparing Your Workpiece

Before diving into the drilling process, it’s important to properly prepare your workpiece to ensure a successful outcome. Taking the time to complete a few essential steps will make the drilling process into hardened steel a breeze.

Marking the Spot

First, mark the exact spot where you need to drill on the hardened steel. This will help you maintain precision and accuracy throughout the drilling process. Consider using a center punch or a sharp object to create a small indentation on the surface as a guide for your drill bit.

Securing the Steel

To prevent the hardened steel from moving or vibrating during drilling, it’s crucial to secure it properly. You can use clamps or a vise to firmly hold the steel in place. This will not only improve stability but also enhance safety during the drilling process.

Making Pilot Holes

Making pilot holes is an effective technique when drilling into hardened steel. Start with a smaller-sized drill bit to create a pilot hole. This will help guide the larger drill bit when drilling through the hardened surface. It also reduces the risk of slipping or wandering off the marked spot.

By following these preparatory steps, you’ll ensure a smoother and more precise drilling process when working with hardened steel.

drilling hardened steel plate

Preparation Steps for Drilling Hardened Steel Benefits
Marking the spot – Ensures precision and accuracy during drilling
Securing the steel – Provides stability and enhances safety
Making pilot holes – Guides larger drill bit and reduces the risk of slipping

Lubricating Your Drill Bits

When it comes to drilling hardened steel, lubrication is a key factor that can significantly improve your drilling experience. By lubricating your drill bits, you can enhance their performance and protect them from excessive heat and wear. In this section, I’ll explain why lubrication is important when drilling hardened steel and provide you with some valuable tips on the best lubricants to use for this specific task.

When drilling through hardened steel, the high level of hardness and resistance can cause intense friction and heat generation. This can lead to premature wear and dulling of your drill bits, making it difficult to achieve precise and clean results. Lubricating your drill bits helps to reduce friction and heat buildup, extending their lifespan and maintaining their sharpness for longer.

So, what lubricants should you use when drilling hardened steel? There are several options available, each with its own advantages:

  1. Neat cutting oil: Neat cutting oils, such as sulfurized and chlorinated oils, are specifically designed to minimize heat and friction during metal drilling processes. They provide excellent lubrication and cooling properties, allowing your drill bits to glide smoothly through hardened steel without significant wear.
  2. Cutting fluid: Cutting fluids, also known as coolant or metalworking fluids, are another effective lubricant choice. These fluids are formulated to reduce heat and friction, prolonging the life of your drill bits. They also have the added benefit of flushing away debris and chips, keeping your drilling area clean and enhancing drilling accuracy.
  3. WD-40: While WD-40 is not specifically designed as a lubricant for drilling hardened steel, it can still provide decent lubrication and cooling properties. When using WD-40, it’s important to apply it generously to the drill bit and the drilling area to ensure effective lubrication and heat reduction.

Pro Tip: Regardless of the lubricant you choose, it’s essential to apply it directly to the drill bit and the drilling area. This will ensure proper lubrication and minimize friction and heat buildup.

Remember to regularly reapply the lubricant during the drilling process to maintain its effectiveness.

By incorporating lubrication into your drilling routine, you can drill through hardened steel more efficiently and achieve better results. Lubrication not only protects your drill bits but also enhances drilling speed, accuracy, and overall performance. So make sure to choose the right lubricant and keep those drill bits gliding smoothly through the toughest of hardened steel!

Applying the Right Pressure and Speed

When drilling hardened steel, it’s essential to apply the right pressure and speed to ensure efficient and precise results. By following the recommended techniques below, you can avoid overheating and achieve optimal drilling performance:

  1. Start slow: Begin drilling at a low speed to establish a pilot hole. This helps prevent the drill bit from slipping and ensures accurate drilling placement.
  2. Increase speed gradually: As you progress, gradually increase the speed of the drill to maintain momentum and avoid excessive heat buildup.
  3. Use constant pressure: Apply steady and consistent pressure throughout the drilling process. Avoid applying excessive force, as it can lead to bit breakage or damage to the workpiece.
  4. Allow the bit to cool: Periodically pause drilling to allow the drill bit to cool down. This helps prevent overheating and prolongs the lifespan of the bit.

Remember, drilling hardened steel takes time and patience. Rushing the process or using excessive force can lead to unsatisfactory results and potential damage. Take your time, follow these tips, and you’ll achieve professional-quality drilling in hardened steel.

“Applying the right pressure and speed is key to drilling hardened steel effectively. By starting slow, increasing speed gradually, using constant pressure, and allowing the bit to cool, you can achieve precise results and prolong the lifespan of your drill bits.”

drilling tips for hardened steel

Technique Advantages Disadvantages
Start slow – Prevents bit slipping
– Accurate drilling placement
– Takes longer to establish a pilot hole
Increase speed gradually – Maintains momentum
– Minimizes heat buildup
– Requires patience
Use constant pressure – Ensures consistent drilling
– Prevents bit breakage
– Excessive force can damage the workpiece
Allow the bit to cool – Prevents overheating
– Prolongs bit lifespan
– Extends overall drilling time

Using Cooling Techniques

When drilling through hardened steel, excessive heat can quickly dull your drill bits and hamper your drilling performance. That’s where cooling techniques come in. By implementing the right cooling methods, you can effectively reduce heat buildup, prolong the lifespan of your drill bits, and improve your drilling results. In this section, we will explore different cooling techniques that can be employed during the drilling process.

1. Lubrication:

One effective cooling method is to use a lubricant while drilling through hardened steel. Lubricants reduce friction and heat generation, making it easier for the drill bit to cut through the tough steel. Apply a suitable lubricant such as cutting oil or tapping fluid to the drilling area before starting the process. This helps to keep the drill bit cool and prevents premature wear.

2. Cooling Agents:

Another cooling technique involves using cooling agents or coolants to dissipate heat during drilling. Cooling agents are specifically designed to lower the temperature of the workpiece and the drill bit. You can use a spray coolant or immerse the workpiece in a suitable cooling liquid to maintain optimal drilling conditions.

3. Air Cooling:

Air cooling is a simple yet effective method to cool down the drill bit when drilling through hardened steel. You can use a high-powered fan or compressed air to blow cool air directly onto the drilling area. This helps to prevent heat buildup and keeps the drill bit and workpiece at a manageable temperature.

4. Multiple Drilling Passes:

Another cooling technique is to divide the drilling process into multiple passes. Instead of drilling continuously, make intermittent drilling passes with short breaks in between. This allows the drill bit to cool down and dissipate heat during the breaks, reducing the risk of overheating.

By employing these cooling techniques, you can ensure that the drilling process remains smooth and efficient even when working with hardened steel. The cooling methods help to control heat buildup, minimize drill bit wear, and maximize drilling performance.

drilling hardened steel

Next, we will explore the importance of effectively managing chip removal when drilling through hardened steel and provide tips on how to maintain a clean and efficient drilling process.

Handling Chip Removal

When drilling through hardened steel, proper chip removal is essential to maintain a clean and efficient drilling process. Chip clogging can lead to decreased drilling performance and damage to the drill bits. In this section, I will provide you with some tips on how to effectively manage chip removal and prevent drill bit clogging.

Tip 1: Use Peck Drilling Technique

One effective technique to manage chip removal is the peck drilling method. Instead of continuously drilling into the material, you can make short drilling intervals and retract the drill bit periodically to clear out the chips.

Here’s how to apply the peck drilling technique:

  1. Start drilling slowly, ensuring the drill bit makes contact with the hardened steel surface.
  2. Apply moderate pressure and begin the drilling motion.
  3. After a few seconds, retract the drill bit partially to break the chips and clear them from the hole.
  4. Repeat the process by gradually increasing the drilling depth until the desired hole is achieved.

Using the peck drilling technique helps prevent chip accumulation and facilitates smoother chip removal during the drilling process.

Tip 2: Utilize Lubrication and Coolants

In addition to the peck drilling technique, applying lubrication or coolants can aid in chip removal and improve drilling performance when working with hardened steel.

You can use a suitable cutting fluid, oil, or coolant to lubricate the drill bit and reduce friction. This lubrication helps break down the chips and facilitates their removal from the hole. It also prevents overheating of the drill bit, prolonging its lifespan.

Drilling Through Hardened Steel

Tip 3: Clear Chips Regularly

During the drilling process, it’s essential to regularly stop and clear out the chips to maintain a smooth and efficient drilling operation. Neglecting to clear chips can lead to chip clogging, which can affect the accuracy and quality of the hole.

After each peck drilling interval, take a moment to remove any chips or debris from the hole. You can use compressed air, a shop vacuum, or a chip brush to clear the chips effectively. Ensuring a clean hole allows for better chip evacuation during subsequent drilling intervals.

By implementing these tips, you can effectively manage chip removal while drilling through hardened steel, ensuring a clean and efficient drilling process. Proper chip removal reduces the risk of drill bit clogging and promotes better drilling performance.

Ensuring Safety

Safety is of utmost importance when drilling hardened steel or any other material. To protect yourself and others, it’s essential to follow proper safety precautions. Here are some important tips to ensure a safe drilling experience:

1. Wear Protective Gear

When drilling hardened steel, it’s crucial to wear the appropriate protective gear. This includes:

  • Safety glasses or goggles to protect your eyes from flying debris.
  • Ear protection, such as earplugs or earmuffs, to reduce noise exposure.
  • Gloves to provide a better grip and protect your hands from sharp edges.
  • A dust mask or respirator to prevent inhaling of harmful dust particles.

2. Secure Your Workspace

Before you start drilling, ensure that your workspace is clean and organized. Remove any clutter or obstacles that may cause accidents or hinder your movements. It’s also important to have a stable work surface or vice to securely hold the hardened steel in place during drilling.

3. Use the Right Drill Bit

Using the appropriate drill bit for hardened steel is essential for both safety and efficiency. Make sure to choose a high-quality, carbide-tipped drill bit specifically designed for drilling through hardened steel. Using a dull or improper drill bit can increase the risk of accidents, such as the bit slipping or breaking.

4. Work at a Controlled Speed

When drilling hardened steel, it’s important to work at a controlled speed. Avoid using excessive force or drilling too quickly, as this can cause the drill bit to overheat and potentially break. Maintain a steady and controlled pace to ensure precise drilling and minimize safety risks.

Proper safety precautions are crucial when drilling hardened steel. Wearing protective gear, securing your workspace, using the right drill bit, and working at a controlled speed are key to a safe and successful drilling experience.

By following these safety tips, you can minimize the risks associated with drilling hardened steel and ensure a safe working environment. Remember, safety should always be your top priority, no matter the task at hand.


In conclusion, drilling through hardened steel requires careful consideration and the right tools. By following the tips provided in this article and using the best drill bits for hardened steel, you can successfully complete your drilling projects with precision and confidence.

Firstly, it is crucial to choose the right drill bits for this challenging task. The best drill bits for hardened steel are specifically designed to withstand the hardness and toughness of the material, allowing for efficient drilling without compromising the bits’ durability. These specialized bits are often made with high-speed steel (HSS), cobalt, or carbide materials, making them more resistant to heat and wear.

Additionally, employing proper drilling techniques such as lubricating the drill bits, applying the correct pressure and speed, and using cooling techniques can greatly enhance your drilling performance. These techniques help reduce heat buildup, prevent premature wear of the drill bits, and improve chip removal, ensuring a smoother and more efficient drilling process.

Lastly, prioritizing safety is paramount when drilling hardened steel. Always wear appropriate protective gear such as safety glasses, gloves, and ear protection. Maintain a clean and organized workspace, free from any potential hazards. By taking these safety precautions, you can prevent accidents and injuries while working with this tough material.


What is hardened steel?

Hardened steel is a type of steel that has been subjected to heat treatment to increase its hardness and strength. It is used in various applications where durability and resistance to wear are important.

Why is drilling through hardened steel difficult?

Drilling through hardened steel is difficult due to its hardness and resistance to drilling. Hardened steel requires special techniques and tools to effectively penetrate the surface.

What are the best drill bits for drilling hardened steel?

Carbide-tipped drill bits or cobalt drill bits are considered the best options for drilling hardened steel. These bits have a high hardness and resistance to heat, allowing them to effectively drill through hardened steel.

How do I drill through hardened steel?

To drill through hardened steel, start by marking the drilling spot and securing the steel. Then, use a sharp carbide-tipped or cobalt drill bit at low speed and high pressure. Apply cutting fluid or lubricant to cool the drill bit and reduce friction. Gradually increase the drilling speed as you penetrate the steel.

How do I ensure safety while drilling hardened steel?

Ensuring safety while drilling hardened steel is crucial. Wear appropriate protective gear such as safety glasses, gloves, and a mask. Work in a well-ventilated area and secure the workpiece properly. Follow the manufacturer’s instructions for the drill and other tools.

What lubricant should I use when drilling hardened steel?

When drilling hardened steel, it is recommended to use cutting fluid or a lubricant specifically designed for metal drilling. These lubricants help reduce friction, dissipate heat, and prolong the life of the drill bit.

How can I manage chip removal while drilling hardened steel?

Proper chip removal is important to maintain a clean drilling process. Use compressed air or a vacuum to remove chips as you drill. Do not let the chips accumulate as they can cause drill bit clogging and affect drilling performance.

Can I use a regular drill bit to drill hardened steel?

It is not recommended to use a regular drill bit to drill hardened steel. Regular drill bits are not designed to withstand the hardness and heat generated while drilling hardened steel, and they will likely become dull or break.

How do I choose the right drill bits for drilling hardened steel?

When choosing drill bits for drilling hardened steel, look for carbide-tipped or cobalt drill bits. These types of drill bits are specifically designed to withstand the hardness of hardened steel and provide efficient drilling performance.

What speed and pressure should I use when drilling hardened steel?

Start drilling at a low speed and gradually increase the speed as you penetrate the hardened steel. Use high pressure to apply downward force while drilling but avoid excessive pressure that may cause the drill bit to break or overheat.