EZ Drill Chuck

This style of adjustable drill chuck (similar to the Dremel chuck) is much simpler than the Jacob's style chuck but it does have one quirk: the jaws move with the tightening ring instead of with the body, and hence, the torque seen by the drill bit makes the chuck self-tightening. But conversely, reversing the rotation (like when backing out screws with a driver bit or when using a left-handed drill bit) will cause the chuck to loosen. So this is really only for one-way drilling/driving/dremelli