Hammer Drill for Metal: A Comprehensive Guide


Hammer drills are versatile power tools that can tackle a wide range of materials, including metal. While they may not be the ideal choice for drilling metal due to their low rotation speed and torque, they can still be effectively used with the right considerations. This comprehensive guide will delve into the key factors to consider when using a hammer drill for metal, such as power, impact rate, individual impact strength, and the appropriate drill bits. By understanding these technical details, physics students can ensure efficient and effective drilling for their construction or DIY projects.

Power Considerations for Hammer Drills

hammer drill for metal

The power of a hammer drill is a crucial factor when it comes to drilling through metal. This power is typically expressed in watts, and the higher the wattage, the greater the power output of the tool. For drilling metal, it is recommended to use a hammer drill with a power rating of at least 500-600 watts.

Cordless hammer drills, on the other hand, measure their power in volts. Bosch, a leading manufacturer of power tools, offers electric hammer machines with 12-volt and 18-volt battery systems, which can provide ample power for drilling through metal.

To understand the relationship between power and drilling performance, we can use the following formula:

Power (P) = Torque (T) × Angular Velocity (ω)

– Power (P) is measured in watts (W)
– Torque (T) is measured in Newton-meters (N·m)
– Angular Velocity (ω) is measured in radians per second (rad/s)

For efficient metal drilling, the hammer drill should have a high torque output to overcome the resistance of the metal, as well as a high angular velocity to ensure a rapid drilling process.

Impact Rate and Individual Impact Strength

In addition to power, the impact rate and individual impact strength of a hammer drill are crucial factors to consider when drilling metal.

The impact rate, measured in beats per minute (bpm), indicates the speed and rate of the hammer drill’s percussive hits. For drilling metal, a good impact rate is around 4,000 bpm. This high impact rate helps to break through the tough surface of the metal and maintain a consistent drilling process.

The individual impact strength, measured in joules (J), represents the energy with which the hammer drill strikes. For drilling metal, it is recommended to use a hammer drill with an impact strength of at least 0.6J. This higher impact strength ensures that the drill can effectively penetrate the metal and create the desired hole.

To calculate the impact energy (E) of a hammer drill, you can use the following formula:

E = 1/2 × m × v^2

– E is the impact energy in joules (J)
– m is the mass of the striking mechanism in kilograms (kg)
– v is the velocity of the striking mechanism in meters per second (m/s)

By understanding the impact rate and individual impact strength of a hammer drill, physics students can select the appropriate tool for their metal drilling needs.

Drill Bit Selection and Shank Diameter

When using a hammer drill for metal, it is essential to select the correct drill bits. SDS-plus drill bits are the ideal choice for drilling metal, as they are designed to withstand the high impact and rotational forces generated by the hammer drill.

SDS-plus drill bits come in a variety of sizes and lengths, allowing you to tackle a wide range of metal drilling projects. To determine the right hammer drill based on your drill bits, you need to measure the shank diameter of each bit.

The shank is the part of the drill bit that fits into the hammer drill itself. You can use a digital caliper or micrometer to accurately measure the diameter of the shank on your drill bits. For example, if your caliper reads 1″, then the shank diameter is 1 inch.

Once you have the shank diameter, you can check the specifications of potential hammer drills you’re considering purchasing. Manufacturers will typically specify the shank types and sizes that their drills can accommodate.

To ensure a secure and efficient connection between the drill bit and the hammer drill, it is crucial to match the shank diameter of your drill bits with the compatible hammer drill. This will guarantee optimum power transmission and enable quick and easy drill bit changes without the need for additional tools.

Tool Holder and Power Transmission

Most modern rotary hammers, including hammer drills, are equipped with the SDS chuck developed by Bosch. This innovative tool holder design guarantees optimum power transmission from the hammer drill to the drill bit.

The SDS chuck, also known as the “Slotted Drive System,” features a unique mechanism that allows the drill bit to be inserted and locked into the chuck without the need for a key or additional tools. This design ensures a secure and efficient connection, enabling the hammer drill to effectively transfer its power and impact to the drill bit.

The SDS chuck’s ability to quickly and easily accommodate different drill bit sizes and types is a significant advantage when working with metal. This feature allows users to seamlessly switch between various drill bits, optimizing the drilling process and reducing downtime.

By understanding the importance of the tool holder and power transmission in a hammer drill, physics students can ensure that their metal drilling operations are carried out with maximum efficiency and precision.

Practical Considerations and Techniques

When using a hammer drill for metal, there are several practical considerations and techniques that can help ensure successful and safe drilling:

  1. Drill Bit Lubrication: Applying a small amount of cutting fluid or lubricant to the drill bit can help reduce friction and heat buildup during the drilling process. This can extend the life of the drill bit and improve the overall drilling performance.

  2. Drilling Speed and Pressure: Maintain a moderate drilling speed and apply steady, consistent pressure when drilling through metal. Avoid excessive speed or pressure, as this can cause the drill bit to bind or overheat, potentially damaging the tool or the workpiece.

  3. Cooling and Chip Removal: Regularly pause the drilling process to allow the drill bit and workpiece to cool down. Additionally, ensure that the drill bit is able to effectively clear the metal chips, as a buildup of debris can impede the drilling progress.

  4. Workpiece Clamping: Securely clamp the metal workpiece to a stable surface to prevent it from moving or vibrating during the drilling process. This helps maintain accuracy and safety.

  5. Wear Appropriate Personal Protective Equipment (PPE): When drilling metal, it is essential to wear safety glasses, gloves, and other appropriate PPE to protect against flying debris, sharp edges, and potential injuries.

By incorporating these practical considerations and techniques, physics students can optimize their metal drilling operations and ensure a safe and efficient workflow.


In conclusion, using a hammer drill for metal drilling requires a deep understanding of the technical specifications and practical considerations involved. By carefully selecting a hammer drill with the appropriate power, impact rate, and individual impact strength, and by using the correct drill bits with the proper shank diameter, physics students can effectively tackle a wide range of metal drilling projects.

Additionally, understanding the importance of the tool holder, power transmission, and practical techniques can further enhance the efficiency and safety of the drilling process. By following the guidelines and recommendations outlined in this comprehensive guide, physics students can confidently and successfully use a hammer drill for their metal drilling needs.


  1. Why do SDS hammer drills have a stat for metal?
  2. All About Hammer Drills
  3. Drills vs. Hammer Drills vs. Impact Drivers
  4. Hammer Drill Bits Explained
  5. Hammer Drill Bit Shank Diameter and Compatibility