Adjustable Clutch on Cordless Drill

An adjustable clutch is what separates electric drills from cordless drill/drivers.

Located just behind the chuck, the clutch disengages the drive shaft of the drill, making a clicking sound, when a preset level of resistance is reached.

The result is that the motor is still turning, but the screwdriver bit isn't.

Why does a drill need a clutch? It gives you control so you don't strip a screw or overdrive it once it's snug.

It also helps protect the motor when a lot of resistance is met in driving a screw or tightening a bolt.

The number of separate clutch settings varies depending on the drill; better drills have at least 24 settings.

With that many clutch settings, you can really fine-tune the power a drill delivers. Settings with the lowest numbers are for small screws, higher numbers are for larger screws.

Most clutches also have a drill setting, which allows the motor to drive the bit at full power.