Will a Hammer Drill Crack Concrete? What You Should Know

Drilling concrete

Concrete is so dense and hard that drilling into it is more challenging than other materials. However, with the proper tools, it is possible to drill without cracking. Which tools suit the job—will a hammer drill crack concrete?

A hammer drill will drill into concrete with a lower risk of cracking when used correctly. Because it vibrates while drilling, the drill bit on this tool makes it perfect for making small holes in concrete as it pulverizes the concrete by hammering into it while the drill bit spins. 

If you are planning to work on a concrete structure, you need to know the correct tools and methods to keep yourself safe and the structure stable. Keep reading to find out everything you should know about drilling through concrete, how to avoid cracks, and which tools are the best for this task.

How To Drill Through Concrete With a Hammer Drill

The following technique and safety precautions will ensure that you can successfully use a hammer drill to drill through concrete properly:

  1. Choose your starting point on a smooth patch of concrete. This process keeps the drill from moving out of place.
  2. Make a small hole to mark your starting point using a hammer and nail. It’s easier for the hammer drill to push through if there is a hole in which the drill bit will fit snugly.
  3. Adjust your drill to the desired depth. If you do not have this option (a depth stop) in your hammer drill, you can wrap the electrical tape at the depth level you want. You will be able to feel the tape and stop accordingly. 
  4. Insert the drill bit. You should be able to secure the drill bit by turning it clockwise after insertion.
  5. Set up your vacuum. Prepping a vacuum is optional to ensure you have less mess to clean after you have finished the job.
  6. Start drilling. Gently, carefully, you can start drilling into the hole. Ensure you have a firm grip on the hammer drill because it is more robust than a regular power drill.

Additional Tips

Make sure that you aren’t continuously running the hammer drill. It is best to turn it off frequently to avoid overheating the motor. Here’s another pro tip: measure twice, and drill once. You won’t be able to correct any mistakes once you start drilling.

Here are a few other preventive measures:

  • Always wear appropriate safety gear.
  • Do not operate power tools when intoxicated or sleep-deprived.
  • Do not press on the hammer drill; let it do the work for you. Otherwise, you run the risk of kickback.
  • Focus your energy on keeping a firm grasp on the power tool in your hands.
  • Use an auxiliary handle if available. It will add pressure to the drill safely.
  • Avoid drilling too deep, as this can cause structural instability of the concrete.
  • Never use a dull drill bit. This error is a significant cause of injury and will expend your energy without any results.
  • If you’re using a rotary drill, lean towards using a smaller size to avoid removing excess concrete

Choosing the Correct Drill Bit for Drilling Concrete

Before drilling into concrete, you should ensure that your hammer drill has the correct drill bit. A masonry bit, also known as a concrete bit, is suited for concrete or other hard materials such as stone. You wouldn’t be able to use the same bit for glass, plastic, or wood. 

You can recognize a masonry bit easily, as it lacks the blunt tip you’d find in a regular drill bit. This feature is characteristic of all masonry bits because the pointed end prevents cracking and ensures that the concrete or stone doesn’t chip as you’re drilling.

These are the features you need to look for in masonry bits for use in drilling concrete:

  • Shank: Concrete bits should have notches so that the drill bit can fit into a hammer drill or rotary hammer because the chuck has a slotted design.
  • Flute: This is the recessed groove along the drill bit, responsible for removing debris. Look for those flutes which function to remove debris faster.
  • Tips: The head of a masonry drill bit is the most durable part of the entire tool because it is where the tool first makes contact with the concrete or stone. Some tips are capable of drilling through steel-reinforced concrete
  • Length: Depending on the application, you may need longer drill bits to create a longer hole in the concrete.
  • Diameter: You will need to know how big you need the holes in the concrete to be. For example, if you are drilling pilot holes, the diameter should match the size of the screw you will install at the end. 

Masonry Bit Types

There are two main masonry bits used to drill holes in concrete. They are the following:

  • Two-cutter head: This head has two cutters on either side and is usually very small. They are helpful only for drilling unreinforced concrete as they might bend more easily.
  • Four-cutter head: This bit has a four-pronged head with cutters forming a cross. They are typically larger and used in drilling reinforced concrete. A 4-cutter head is considerably faster and more durable. 

Difficulties and Dangers You May Face While Drilling Concrete

Drilling concrete is no easy feat; this job has hidden hazards and dangers. 

Below are a few challenges or dangers you may face when drilling through concrete:

Silica Dust

Many construction workers ignore the dust that inevitably comes with drilling concrete. Silica dust is a significant breathing hazard and causes serious illness. You should not take it lightly. Ensure you wear the correct mask when drilling to prevent yourself from breathing the silica dust.

The correct mask is an N95 or KN95 mask because it has filters that keep out the fine silica dust. Ensure you wear the mask properly for the entire duration of your work at the construction site when drilling. 

Cracking Concrete

As you’d expect, concrete is prone to cracking. Any mistake while drilling, such as hitting a large piece of gravel, will result in a crack in the concrete. Unfortunately, fixing the damage is not easy. This potential issue is why choosing the correct drill bit and carefully measuring it is extremely important when working with concrete. 

Instability

While durable and robust, concrete structures can suddenly become unstable when cracked or drilled. If you are wrong about your measurements, there is a real risk that the entire structure could collapse on you and your construction crew. You risk fatally injuring multiple people even if you’re a few inches off. 

Kickback and Overheating Injuries

Lastly, not using the correct tools and drill bits for the job will likely result in overheating and kickback. Overheating is when the motor of your power tool gets too hot as it exerts too much energy to try and keep up with the increased load you’re putting on it. This issue could result in surface burns or even an electrical fire. 

Kickback is a term used to describe when a power tool slips out of your hands because it couldn’t handle the task you’ve given it—such as when using the wrong tool to drill through concrete. The same thing can happen with other tools, such as a power washer or a sander. The potential for workplace injury from using the wrong tool is endless. [Can You Power Wash Instead of Sanding? Three Things to Know]

Can Other Tools Drill Through Concrete?

A hammer drill isn’t the only tool that can break through concrete. A rotary hammer is capable of doing the job in a pinch. However, several problems arise when using a rotary hammer: 

  • The rotary hammer’s motor is more likely to overheat. Because the rotary hammer doesn’t vibrate the drill bit up and down like a hammer drill, it has to do a lot more work to pulverize the concrete.
  • The concrete is likely to crack. You’ll find that the rotary hammer doesn’t move the drill bit optimally to prevent cracking. 
  • It will take a very long time. Although you can do the job, it will take a lot of patience to drill even a tiny hole.

Hammer Drill vs. Jackhammer

It is easy for laypeople to confuse hammer drills and jackhammers because of the similar motions of the bit that protrude from them. However, it’s worth noting that they are two completely different tools designed for specific purposes. 

A jackhammer functions to break concrete, so workers typically use it in demolition. Manufacturers design hammer drills for drilling, requiring only a small area of the concrete to be pulverized, leaving the rest intact.

Final Thoughts

Drilling concrete with the proper tools and techniques shouldn’t be too difficult. As long as you take reasonable precautions, the risk of cracking is relatively minimal. A hammer drill is perfect for drilling small holes into concrete, whereas a jackhammer is more suited to breaking the concrete up. 

You could use other tools for the same job but would do it less efficiently. Always ensure that you place safety first and wear proper protective gear—especially a good quality mask to protect yourself from the harmful silica dust.

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