What is an SDS Hammer Drill? – (Do you Really Need it?)

When I tried to use a concrete beam using a hammer drill, it took much time and effort. So I decided to use a better tool for my job. So I could find a piston-based hammer drill that is high efficient than a regular hammer drill. It is called a Slotted Drive Shaft (SDS) hammer drill. So let’s see What is an SDS hammer drill?

SDS hammer drill is a more powerful and efficient hammer drill due to its piston-based hammering mechanism. SDS, SDS plus, and SDS max are the types of SDS hammer drills and all these have a special chuck and drill bit. It will cost about 250$-350$. It is about 65% more efficient than a regular hammer drill.

In order to drill concrete and concrete with steel, you will need this heavy-duty tool. When you use it, you should know its usage, mechanism, differences, and much more depth. So keep reading on to grab all.

Hammer Drill and SDS Hammer Drill

How Does a Hammer Drill Work?

The Hammer drill works as a combined chuck and drill bit with moving forward, backward, and rotating. Chuck with drill bit can move about 2mm. Hence, it can’t use for heavy-duty tasks.

How Does an SDS Hammer Drill Work?

The SDS hammer drill chuck and drill bit move separately. The drill bit can freely move forward and backward inside the chuck about 10mm and every time, it gets hit by the piston mechanism.

Hence, it is a more powerful hammer drill rather than a regular hammer drill.

All are the same with the mechanism, and some small differences are there. A conventional hammer drill works with a bearing and clutch. But The SDS hammer drills work with piston mechanisms.

SDS hammer drill is the biggest brother of the hammer drill. There are types of SDS drills. SDS, SDS Plus, and SDS max are them.

This is the inner mechanism of the SDS hammer drill. You can see its name and its functions in a simple way.

Parts and Functions of SDS Hammer Drill

SDS Hammer Drill Mechanism
SDS Hammer Drill Mechanism

01. Power Motor – Motor provides the power to the drill. The motor is powered by a cordless or corded power source. Brushless motors are more powerful than the brushed motors

02. Rotary action wheel – This wheel produces the rotary action of the SDS hammer. In SDS, there are both rotary and hammer actions. You can see that wheel is connected to another horizontal rotation

03. Piston – Piston is used to produce the hammering action. If there is a direct mechanical action, the motor and drill bit, the hammer can be damaged due to high power thrust.

04. Piston head – When the motor rotates, the piston will be moving forward and backward, and then it can compress the inside air. There is another piston in front of the piston head. So it also moves like a piston head and moves forward and backward.

05. Hammer Head – When the moving piston hits on the hammer head with much power, it also can move forward and hit the drill bit. The number of the drill bits movements is called blows per minute (BPM)

06. Chuck – To hold the drill bit, chuck is used. Here chuck is not moved like a hammer drill, and only the drill bit will move forward and backward.

07. Support handle – The support handle needs to apply more support to the machine when it drills.

08. Drill bit – The specially designed drill bit is used for the drilling process.

This is the simple way of the SDS hammer drill explanation.

Read more – How Does a Hammer Drill Work?

There are suitable seals inside the tool, and those will not leak the air. These pistons are used air pressure to move to each other. If there is any connected mechanism with the piston and drill bit, the motor will be damaged due to back force. Air is compressible, and hence it can hold the back force by increasing the air pressure.

How to Operate the SDS Hammer Drill?

SDS hammer drill can be operated a bit hard. It is totally used for heavy-duty works. So there is a handle you can use for easy handling. Consider the SDS hammer drill. There are 3 modes.

  1. 2 modes – Drill and Hammer Drill mode
  2. 3 modes – Drill, Hammer, and Hammer drill mode

That will depend on the tool you use. Hammer-only models can use a chisel. It can be used for demolitions.

  • First, you need to mound the appropriate drill bit to the chuck
  • Then set the drill mode as you need. For the concrete use rotary and hammer mode. If you selected hammering mode, you can use the chisel
  • Hold the tool tightly with grips and start the drilling. You will need more force to hold the tool.

Drill Bit and Chuck Differences in SDS Hammer Drills

The drill bit is mounted to the chuck. SDS is like a hammer drill. But the hammering mechanism and chuck are different.

Normally in the hammer drill, the chuck is moved forward and backward about 2mm. But in the SDS hammer drill, the drill bit is moving forward and backward about 10mm.

  • Here the chuck is not moving and there is a special mechanism to hold the drill bit.
  • Hammer drill bits are circular, and the chuck has 3 jaws to tighten the drill bit. The drill bit will not move too much due to this. Because it does not use for heavy-duty work such as hard concrete drillings.

SDS drills need more torque and drilling power. According to the inside mechanism, the hammer head is hit on the tool head. The tools freely move forward and back work at a certain distance. This was fixed with a ball bearing, and this can provide the maximum force into the material without damaging the tool.

Drill Bits for SDS hammer drills
Image Source

4″ Concrete Beam and SDS Hammer Drill Test

You can use any hammer drill, SDS plus, or SDS max. But the final result will be different for the different kinds of material. This test is done for the 4″ concrete beam, and drilling time was measured with various drills. So you had better take a look into this and have an idea about the selection.

Drill TypeDrilling Time
Drill/Driver1 min 20 sec
Hammer Drill20 sec
SDS plus11 sec
SDS max7 sec
Drill Types and drilling time

You can observe how much SDS max and SDS plus act.

Why Do You Need SDS Hammer Drill?

SDS hammer drills are really good at heavy-duty works such as drilling concrete and reinforcement together, drilling stones, chiseling, and many more tasks with higher efficiency.

Some regular hammer drills are not able to use deeper into the concrete. But SDS hammer drills can be highly recommended for that.

SDS (rotary hammer) hammer drills are more important for heavy-duty work. If you use a regular hammer drill on concrete, you have to stop the drilling when there is reinforcement. You will need a rebar cutter and then a drill. But if you use the SDS drill, you can drill continuously with the more powered carbide tips.

In the SDS drill, we can change the working types. There are mods like driving, hammer drilling, and rotary hammer. We can use a chisel under the hammer mode, which will act like a breaker.

Can I use SDS Drill Bits on Regular Hammer Drill?

Shortly you can’t use the SDS hammer drill bits on the regular hammer drills. The reason is engraved shank will not fix with the jaws of the chuck. Even if you mounted, it would not straight forward due to engraves. When the jaws are tight, it can be to stand straight forward.

Can I use Hammer Drill As a Chisel?

You are not able to use a hammer drill as a chisel because regular hammer drill hammering action does not have much power, and it can’t mount the chisel.

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Tom Mackency

Tom Mackency

Hi, I am Tom Mackency. It has been 10 years that I have been working as a professional woodworker since 2013. I am really enjoying my carrier by creating many kinds of projects in my workshop. But mostly I like for home improvement projects. Home improvement and DIY projects are the most interesting things for me. More than that, the coolest things are power tools. Those are very precious and efficient than a decade ago. So I try to introduce so many things about power tools, woodworking, DIY projects, home improvement and many more interesting topics here.