Some DIYers feel that a cordless impact driver’s disadvantage is in its lack of a 3-jawed chuck. 3-jawed chucks can be found on tools such as cordless drill drivers and, as the name suggests, have three jaws which open and close to hold a variety of different size screwdriver and drill bits.
3-jawed chucks are popular with users because they allow bits with round shanks as well as hexagonal shanks to be used. Most drill bits have round shanks, so using a 3-jawed chuck allows you to drill a wide variety of holes.
3-jawed chucks can be found on cordless drills but not on cordless impact drivers. This is because cordless impact drivers are specifically designed to drive screws, rather than drill holes of various sizes.
3 jaw conversion chucks
An accessory called a 3 jaw conversion chuck is available that allows you to use round shanks in your cordless impact driver. One end has a hexagonal shank that fits into the cordless impact driver’s chuck, while the other end has a 3-jawed chuck to accept round shanks.
Some models are keyless and will have an adjustable collar that rotates clockwise and anti-clockwise to open and close the jaws. Other models require a key to open the jaws, which should be included with the chuck itself.
A popular use for the conversion chuck is to allow the cordless impact driver to be used like a drill and accept drill bits with round shanks.
