Keyed chucks
The keyed chuck is a common type of chuck for drills. These chucks can be recognised by their toothed gear ring. To turn this ring, you must use a chuck key, which opens or closes the three jaws inside the chuck. The jaws hold the tool solidly in the drill chuck. In order to clamp a tool as uniformly as possible, you should tighten the chuck strongly in all three holes surrounding the toothed ring.

Keyless chuck
Bosch's Keyless Chuck simplifies tool changes because you no longer need a special key. Keyless chucks can be identified by their profiled rotating sleeve. Of course, all drill chucks on Bosch impact drills are impact resistant.

Dual sleeve keyless chuck
Dual sleeve keyless chucks have two rotating rings for opening and closing the chuck. The tool user holds one ring stationary while opening or closing the other.

Single sleeve keyless chucks 
Single sleeve keyless chucks are easier to operate than the dual sleeve types. Single sleeve chucks are used with a spindle locking device. This is the most comfortable way to change tools.

BOSCH Press + Lock
By pressing the Press+Lock button on the top of the drill, you can lock the drill spindle and then open or close the chuck with a simple rotation. With this system it is even easier and more comfortable to change tools than with traditional keyless chucks. Attention: It is normal for a drill to continue rotating for a few seconds after it has been switched off. Do not use the button to stop this rotating motion. This will break the Press + Lock mechanism.

Bosch Auto Lock
The Auto Lock system is an innovation in impact drills that simplifies tool changes. We call the system Auto Lock because the device automatically locks the spindle when it is at a standstill. Now the drill chuck will open more quickly and easily with just a simple turn.