Multi-jaw

Multi-jaw

For special purposes, and also the holding of fragile materials, chucks are available with six or eight jaws. These are usually of the self-centering design, and may be built to very high standards of accuracy.
Two-jaw chucks are available and can be used with soft jaws (typically an aluminium alloy) that can be machined to conform to a particular workpiece.
Many chucks have removable jaws (often the top part is removable leaving the base or 'master jaw' assembled with the scroll), which allows the user to replace them with new jaws, specialized jaws, or soft jaws.

An older and larger 4 jaw chuck. Note how it is able to grip an irregularly cut piece of used metal. Though not found on small chucks it is common for larger chucks (the one in the second photo was made around 1900 and is 24" in diameter) to have many of the features of a Lathe faceplate. The jaws are stepped on one side and full height for gripping on the other and are reversible. Generally the jaws are usable for holding either outside as shown here, or inside as in gripping the inside of a pipe.