The impact drill owes its name to the impact function, which you can set for drilling in hard-stone types. With the button set to ‘drill’, the machine works the same as a regular drill. And if you set it to ‘impact’, the drill not only spins but also moves vigorously up and down — kind of like a hammer pulverizing the stone. Impact drills are available both with mains power and with a battery.
How does the impact function work?
On the shaft of the machine is a round disc with serrated teeth on one side along with another toothed disc is mounted in the machine. When the impact function is off, the discs do not touch each other, but if you switch it on, the teeth of both discs interlock. The rotation of the shaft produces a strong vibrating movement, which allows you to pulverize stone with an impact drill.
Drilling with or without impact function
Depending on the material you are going to drill, you can turn the impact function on or off.
- Drilling in concrete, hard stone or masonry? Turn on the impact function.
- Drilling in softer materials such as wood or plasterboard? Switch off the impact function to prevent the drill holes from becoming too large.
- Drilling in tiles? Turn off the impact function to avoid cracks. and turn on the impact function as soon as you go through the tile and drill into the wall.
- Screwing? Turn off the impact function and run the machine at a low speed.
Set torque and speed
The power of an impact drill is determined by the torque — the turning force of a drill. The torque is expressed in Nm (Newton-meters). An impact drill has different torque settings, which you can adjust by turning the adjustment ring. The higher the torque, the more powerful and faster you can drill. The right torque depends on several factors, such as the material you are drilling in, the diameter of the drill bit and the type of drill bit.
- The harder the material, the lower the torque and the slower you drill.
- The smaller the drill diameter, the higher the torque and the faster you drill.
The correct speed is also crucial. An impact drill usually has two gears, one for drilling and one for screwing. A low speed means more torque, while a high speed means less torque. Screwing is best at low revs, drilling at high revs.
You can read about what the different buttons and sliders on a drill are for and how to use them to set up the machine for a variety of jobs in Setup your drilling machine: this is how you do it.
Working safely with an impact drill
Working with power tools always involves risks. Work concentrated and protect yourself with safety glasses and hearing protection. The latter is especially important because of the high noise level when you work with the impact function.