These 10mm angle drills use the keyless chuck system which means that the drill bit can be changed by hand without the need of a chuck key. This makes these drills highly practical as the drill bits can be changed quickly by hand. Angle drills are useful tools to have for drilling applications which are in tight and confined spaces. These drills do not feature a hammer action, so they are not suitable for drilling concrete or stone and are generally used to drill wood, plastic or metal.