How to Drill through Rebar in Concrete

Rebar is reinforcing steel used in concrete to make it extremely durable and stand the wear and tear of time and weight. That’s why it’s not a piece of cake to cut the Rebar. Then, how to drill through Rebar in concrete?

Well, keep in mind this process can be loud, dusty, and physically exhausting. At the same time, it can expose workers to lung-damaging silica dust. And the level of hands vibration and noise you’ll encounter during this process will be far above recommended limits.

But in this era of technology and internet connectivity around the globe, you can make your job easier by grabbing the right drilling tools. You must know how much drilling you need and make your choice accordingly to keep yourself safe from any hazard. Moreover, try to use proper safety equipment and wears to reduce the life taking dangers.

If you don’t know how to drill through Rebar in concrete safely and have many related questions, continue reading with us to answer all your Rebar drilling-related queries!

Protective Measures Before Drilling Through Rebar in Concrete

Some extra care and precautionary measures are required while drilling in concrete. Some of the essential protective measures are:

▶ You must-have equipment for personal protection to keep yourself protected from the dangers of drilling concrete. At a minimum, you must have eyeglasses with side shields and a tightly fitting respirator. Besides this, glasses or a full-face shield are extensively better. When you drill through the Rebar, bit breakage is common, so you’re advised to protect your eyes and face from harmful metal projectiles.

▶ You must make accurate size and spacing information to know where you’ll encounter Rebar while drilling and make your adjustments accordingly.

▶ You should measure and mark the site for drilling and select an appropriate bit for your pilot hole. Keep in mind that the pilot hole must be three to four-time smaller than what you want to get at the end.

▶ The thing which you never ignore is that drilling through Rebar can weaken the concrete structure, so you must take the help of some professional or structural engineer if you’re just new to this project.

Learn how to drill holes in Plexiglass without cracking.

How hard is it to Drill through Rebar?

Concrete has such a high compression strength that you can even drive vehicles on it without crushing it. This tensile strength of concrete is due to rebar or reinforcing bar. When the rebars are so sturdy, you’ll find it hard to drill through them. Let’s discuss which complications you can face and their possible solutions.

▶ Many times, concretes are made more durable by adding steel rebar into the mix. Although hammer bits are excellent to cut through tough concrete, they might get stuck at steel reinforcements. What can one do at that time? Here, the diamond coring bits can do the trick as they can cut steel rebar like butter.

▶ Most of the time, you drill a hole in concrete but remain unable to cut the Rebar to deepen the hole. Here, you can do different tricks. Firstly, if you’re using a 4-cutter SDS drill bit, don’t pause drilling as the four carbide blade cuts through the steel bar without breaking. But if you’re using any other masonry bit, you should take a break from drilling and swap out the bit to regain original performance.

▶ It’s possible that while going through the hole, you can’t see any rebar. Then don’t sit back, rather try to use a vacuum and compressed air to clean the hold and shine the light inside to find the Rebar. Why can’t you see Rebar when it’s there? An air pocket or a large rock may have encountered you.

▶ The most common problem which almost all people encounter is perfectly determining the vertical or horizontal alignment of the Rebar. You can’t cut Rebar effectively till you know its exact position. But we have got a trick for you. Look at the ridges. If they are perpendicular to the floor, you’re going to encounter horizontal support. At the same time, the parallel ridges indicate that the Rebar is aimed at vertical reinforcement.

▶ When the tip of your bit touches the Rebar, you may lose control over the drill. At that time, you can overcome this issue by simply dropping the drill and starting again with greater accuracy.

Will a Concrete Drill Bit go through Rebar?

This statement isn’t always true. The concrete drill bit, which is strong enough to cut the reinforced concrete slabs, will go through the Rebar, but those designed to cut only bricks and cement-based material won’t go through the Rebar. When you are doing the operation with a concrete drill bit, stop drilling as it hits the Rebar, and there replace the concrete bit with the metal bit to do the right trick for you.

Drilling through concrete is tough, and when the masonry drill bit comes across any piece of Rebar, the project will come to a halt. On the other hand, abrasive bits are efficient to grind through steel rebar, and sharp-edged drill bits are more effective and faster to cut the Rebar.

What Size and Kind of Drill Bit will go through Rebar?

As rebars are built strong to hold your back against any accidental falls when used in concretes. When it comes to cutting the Rebar, you must know which drill bits are there to get your project done. The below-mentioned drill bits have proved excellent to cut through Rebar.

1- Concrete Saws

A concrete saw, sometimes called a circular saw, is widely used to cut through concrete Rebar. They are more powerful than most other saws, so you can expect to get a certain diameter on each blade. The diameter range from 4 to 36 inches is available to do the trick, and you will find it the best way to drill through Rebar in concrete.

2- Diamond Core

We know that diamond is harder than steel, so the diamond-based bits take the heart of reinforced concrete cutters. So, the metal drill bits with embodied diamond pieces are marked as industrial standard to drill through Rebar. They are made universally compatible by providing the users with every possible diameter to drill through reinforced concrete effectively. But keep in mind that diamond core bits are excellent to make larger holes.

3- Tungsten Carbide

Tungsten carbide bits are now widely taking a prominent place in the market due to their high-end functionalities. As they are relatively new technology, they are a bit more expensive and available only in a limited number of sizes. But new sizes are coming with the emergence of more recent models. If you need to make smaller holes of up to 1 1/2 inches in diameter, this bit will suit you the best. Overall, it’s a good drill bit for concrete and steel.

4- Cutter SDS

This workhorse bit incorporates four carbide cutting blades, and it didn’t break while drilling through hard Rebar. If you aren’t interested in trading out bits, then a 4-cutter SDS bit must be your priority choice.

5- Steel Twist Bits

On the clear ground, steel twist bits are designed to drill through metal or tiles, and they are excellent in their specialized field. But keep in mind that regular steel bits aren’t perfect for cutting Rebar. The reason is that they can break after a short period of drilling, and we know well how dangerous broken bits can be. So, we don’t recommend steel bits for drilling through Rebar in concrete.

Can you Hammer through Rebar?

The short answer to this question is “YES.” If you need to drill through the reinforcing bars, any hammer drill or rotatory hammer with a bit designed for concreting can do the job for you. But keep in mind that hitting the Rebar isn’t a good approach by any means, so try to be careful.

Stunningly, if you need an ordinary hole of fewer than 1 1/2 inches diameter, even a rotary hammer can do the trick for you. You must know that the bit can hang up when it hits Rebar, so you must kick back the drill at this event.

If you’re going to hammer through Rebar, you must be aware of BRM, Beats Per Minute, and tell the pounding power of the hammer drill. Also, keep in mind that all-metal chunks are proven durable than the ones with plastic parts. If you make a hole of a certain size, try to grab the chunk of relevant compatibility.

Can you Drill concrete with a Regular Drill?

Yes, you can drill concrete with a regular drill. Many people think that you can’t drill concrete with a standard drill. They believe that there must be a hammer drill with hundred drill bits to pass through concrete. But the reality is different. You can even drill concrete with a regular drill.

Although stronger hammer drilling equipment can make the job faster, they are not necessary by any means. The good thing is that the procedure of drilling in concrete no matter you’re using a regular drill or a hammer drill. Hold in there, and you need more practice and a wider array of drill bits when using a standard drill for the task.

To smartly perform with the regular drill, consider following the given steps to make your job easier.

Step#1: Preparation

Firstly, mark the center of the spot where you want to drill a hole. Next, start your job with the smaller drill bit and continue to apply steady pressure. If at any point you feel that the drill bit is getting stuck, try to back off the bit before starting the drilling again. Failure to stop the drill at harder points can result in broken drill bits.

Step#2: Change Bits Size

When you get your first drilled hole, consider increasing the drill bit’s size and re-drill the hole. Make sure to increase the size of the drill bit a little at a time to get more effective results. Try not to jump more than 1/8 inches of size at a time. If you skip too many drill bit sizes for Rebar in concrete, you might end up with a broken drill bit.

Step#3: Finalize your Work

While drilling with a regular drill, you might encounter new spots which require you to stop drilling and change the drill bit size. Once you get enough larger holes, use some hardened nails to break up the concrete before drilling.

In this way, you would be able to go through more challenging sections of the concrete without using a hammer drill. Once you have your desired hole, place a sturdy nail and hammer it with reasonable force to break the concrete aggregate.

Best way to Drill through Rebar in Concrete

You can drill through the rebar in concrete by drilling with a diamond core bit. A diamond core bit will drill through the hardened steel of the rebar more easily than standard bits, so you’ll need to use less force.

How to Avoid Rebar when Drilling Concrete?

You can only avoid Rebar when drilling through concrete when using mild cutting equipment and better know how to identify the Rebar when it comes on your way. You can prevent Rebar by following methods.

While cutting through the concrete, you might feel at some points that more force is required to move further. Don’t rush and stop right there and try to move the bit slowly. If it hits hard to the coming item, then stop further drilling. You are hitting rebar drilling concrete, and now it’s up to you to cut the Rebar or skip that part.

▶ If you don’t want to hit the Rebar accidentally, you should follow the given steps to avoid cutting Rebar when drilling through concrete.

▶ Make a drilling spot from where you want to cut the concrete.

▶ They make a shallow hole called a pilot hole with the aid of a smaller bit.

▶ Continue drilling with more power and keep the drill perpendicularly in the exact place by applying enough pressure.

▶ If now you want to avoid the Rebar, pull out the drill periodically, clean the hole and shine it with some intensive lighting source to look for any rebar.

▶ If you’re finding it hard to manually identify the Rebar, keep an eye on the drill. If bit feels any recoil or kicks from the drill, stop operation as you now have encountered Rebar.

Final Words

Keeping the long story short, rebars are excellent to improve the tensile strength of the concrete. As they are built extra sturdy, so most people are finding it challenging to cut the Rebar. That’s why we’re often asked that “How to drill through rebar in concrete?”.

We explained in this guide to teach you the nitty-gritty of rebar concrete drilling, associated risks, and ways to overcome any difficulties you can encounter to get your job done.

Bahram Shahab
Bahram here! A certified Electrical Engineer who knows his way around using power tools like a professional. My journey of using these robust tools started back when I graduated. Since then, I have finished almost a dozen DIY woodworking jobs. Apart from that, I have developed this habit of jotting down my personal experience about using a specific tool. So, I write on them to help the community in the best possible way.