Clamping mechanism fitted to the spindle of a drill, the purpose of which is to hold the accessory (e.g. drill bit). The keyed chuck is tightened using a chuck key.
Clamping device on the power tool that allows for quick accessory changes without additional tools (e.g. chuck key). Only accessories with an appropriate clamping shank (e.g. screwdriver bits) can be clamped in the keyless chuck.
Joining element that can be tightened by hand without tools. Instead of a screw head, knurled screws have – as their name states – a knurl, which can be gripped. They are normally locked with nuts that also have a knurl.