Hammer drills are widely used domestically and on construction sites. When using a hammer drill on concrete, it should drill the rebars. So will a hammer drill go through steel? Here I have prepared an in-depth answer to that question as you can drill both concrete and rebars together.
Hammer drills can go through steel in the concrete, by using a HSS drill bit and rebar cutter. HSS drill bit is used for drilling the concrete and rebar cutter for steel cutting. Using a high-grade hard metal drill bit can drill both concrete and steel without changing the drill bits.
Hammer drills are highly effective on hard materials such as concrete, stones, and many more. Mostly we used concrete which is reinforced. So you will not be able to identify the reinforced bars by looking out. So this guide is for identifying such places and drilling with hammer drills. Let’s see how much extent a hammer drill is suitable for drilling steel.
How to Use a Hammer Drill to Drill Concrete and Steel?
When you use hammer drill for concrete, you should know there is rebars (steel) inside. So, when you drill a hole , you have to drill both concrete and steel together. How you can do it?
You can use one of these 03 methods for this.
You can drill the concrete volume using a hammer drill and drill bit. When the rebar is found, you can use a rebar cutter to drill through the rebar.
Normally, rebar cutter size should be higher than drill bit size.
There are high-grade hard drill bits. Those can be used with hammer drills. Using these drill bits, you can drill concrete and rebars (steel) together. No need to take away the drill bit and there is no drill bit changes.
You can use SDS plus or SDS max drills. Which are highly recommended for both concrete and steel drilling purposes. SDS Plus Vs SDS Max: Which One Do you Need?
How to Observe the Invisible Reinforcement in Concrete?
Concrete is high strength for compression and less strong for tensile strength. To increase the tensile strength of the concrete, reinforcement is used. Sometimes reinforcements are also used for compression too. But mostly for tensions. In the construction, we need to do so many works on the concrete. It will need to drill and cut etc.
Normally concrete is with many strength classes. 25 MPa is widely used for domestic purposes and special tasks. It can be 35 MPa, 45 MPa, or higher. Working with this kind of strength needs more power and more strength of the machine.
The eye can’t see inside reinforcement. So you will need additional support for that. 2 main methods can observe inside reinforcement in the concrete.
The principle of the radar method is used in this method. Electromagnetics is used with a small pulse into the target concrete and then determines the reflected pulse using a special antenna. Using an outgoing and receiving time period, the distance is measured. According to the age of the concrete, this can be changed. Read more about the radar method.
Electro Magnetic method
The principle of the electromagnetic method is that an electromagnetic field excited by a probe is detected using a search coil, then the in-place locations, directions, and diameters of the rebars are determined based on the variations of the electromagnetic field.
Using one of these methods or any method for detecting the metal is highly useful for concrete drilling. But if you need to drill without neglecting the reinforcement (not much for the structure much). Let’s see how to hammer drill through the steel?
Use a Hammer Drill Instead of Regular Drill
Drilling inside the concrete with reinforcement is high strength activity. Both concrete and steel are high strength, and for drilling, we need a more high-power drill bit and drill. When you buy a drill, there are so many drills in the market. Hammer drills, rotary hammer drills, SDS drills are a few of them.
When considered a regular drill, it is used for the wood (not too hard). But other drills are designed for special tasks such as drilling steels, concrete, and stones. The best option for the domestic is a combi drill, which can be used as a regular drill, hammer drill, and impact driver. It is not many expensive considering other specialized drills.
So when you choose a hammer drill instead of the regular drill is the best option for both hard and soft works. Consider a regular drill mechanism it is spinning with high speed and low torque. When you consider hammer drill, there will be a hammering and spinning option as a combination. This process increases the drilling speed with low power. You do not need to push too much to the drill.
When drilling through the steel and concrete, you will need special drill bits and more power drill machines.
Best Drill Bit, Power, Torque and Speed of the Hammer Drill
A special drill bit is needed for the concrete drilling using a hammer drill. Normally drill bit should be high strength than steel and concrete. Else it will be melt or break. Drill bits are made with special materials. Those can absorb high heat and hold more strength. Drill bits are made with HSS, carbon and cobalt.
High-Speed Steel (HSS) – For the drilling metal, concrete, stones etc
Soft Low Carbon Steels Bits – Only for drilling and cutting wood.
When you use a drill bit, make sure the drill bit has been made with HSS. More than that, there are drill bits such as Cobalt steel, Tungsten carbide, and Polycrystalline diamond (PCD). Those are made for special tasks.
Not only are drill bits strength but also drilling machines also should be more powerful. Both torque and speed are the main factors for the drilling process. Normally hammer drills are high torque with high speed considering the regular drills. Hence hammer drills can be used as concrete drilling with reinforcements.
Smaller holes such as 1/4″ – 1/2″ is not usually impacting the torque and the RPM.
For bigger hole such as 1″ is affect the torque for the spins due to high resistance.
|Drilling Method||Hole diameter||RPM||Blows Per Minute|
|Fast Spiral Rotary||1/8″ to 1″||450-700||–|
|Rotary||1/8″ to 1″||1300-3500||50,000|
|Rotary Hammer||5/32″ to 1″, 3/8″ to 1-1/2″||400-1000||4500|
The most suitable way is cutting the reinforcement with using the rebar cutter is the best way to save and life long of the hammer drill. Some drill bits are not able to drill through the steel. Hence it is better to cut the rebar and then continue the drilling process with a hammer drill.
When drilling concrete you will need to push more if you don’t use a hammer drill. Because the hammering process will crush inside particles smoothly and take out from the “flutes,” hammer drills do need much push for the drilling process.
When you meet the reinforcement to the drill bit you can observe the noise difference. If you are used a drill bit that can drill the steel also push it more. If you do not use that drill bit, take it out and cut it with the same diameter rebar cutter. So then you can continue the drilling process.
This is the way of Hammer drilling through concrete and steel. Wisely select the drill bits for the drilling process.