Chuck for mounting workpiece

A chuck for mounting workpiece, comprising:

• a chuck body made of an aluminum alloy and comprising at least one guide portion;
• a reinforcement portion disposed in the chuck body and including an inner side surface which forms a sliding portion;
• and
• a base jaw mounted on the chuck body and including a body portion disposed in the at least one guide portion and a support portion protruded from the body portion and disposed in the sliding portion,
• wherein the reinforcement portion comprises the inner side surface directly contacting with the support portion and an outer side surface directly contacting with a surface of the chuck body,
• wherein the outer side surface includes a repeated pattern formed by a plurality of depressed portions and a plurality of protruded portions, and both of the plurality of depressed portions and the plurality of protruded portions are in direct contact with the surface of the chuck body such that a contact area between the chuck body and the outer side surface increases,
• wherein the surface of the chuck body directly contacting with the outer surface is formed of the aluminum alloy, and
• wherein a distal end of the reinforcement portion in a radial direction of the chuck body, which is disposed adjacent to an outer circumferential surface of the chuck body, is positioned inside the chuck body and covered by the chuck body without being exposed to the outer circumferential surface of the chuck body.