Chuck is the machine that clamp work uses on the machine tool. Use all the radial that cloth blocks claw in the activity on chuck body is mobile, the machine tool accessory of workpiece clamp and fixed position. Chuck blocks claw and card claw by chuck body, activity commonly 3 parts comprise actuating device. Chuck body diameter is the smallest for 65 millimeter, can amount to 1500 millimeter most, there is via in the center of, so that carry workpiece or good material; Back has cylindrical or short cone-shaped structure, direct or through flange dish carry department posture connection with machine tool main shaft. Normally installation is in chuck lathe, cylindrical grinder and inside use on round grinder, also can cooperate with all sorts of graduation device, use on milling machine and drilling machine. To make machine tool treatment can gain better precision and stability, chuck also was become important ” add cent ” . Chuck basically has domestic chuck and import at present in the market (Taiwan area, abroad) chuck these two kinds. Domestic chuck respect, the numerous annulus of Yantai, Huhhot (round-the-world) holding majorrer market share, other and main still include Er of Changzhou division rich, changzhou actor bit, changzhou times get happiness, changzhou name card is waited a moment. 60% what sales volume of Taiwan area chuck takes entrance chuck market, korea also is had quite one share share, the Japan of former outfit and Euramerican chuck are belonged to in high-end product. Can divide from chuck claw number for: Two ungual chuck, 3 ungual chuck, 4 ungual chuck, 6 ungual chuck and special chuck. Can divide from use motivation for: The hand moves chuck, pneumatic chuck, hydraulic pressure chuck, dynamoelectric chuck and mechanical chuck. Can divide from the structure for: Hollow chuck and in solid chuck. In fact, manufacturing technology of home is completely capable that production gives product of high grade chuck, but main problem depends on heat treatment and detail craft processing going up to have bigger difference with entrance chuck. Increase cardinal number of home market user big, competition is intense, the manufacturer must not control product cost possibly very much, exchange market competition ability with inferior price. This caused a few problems with domestic common chuck, such as stability bad, service life is brief, repeat precision to maintain time weak point to wait. The process that because its are strict,great majority imports chuck, make sure stable chuck repeats clip to run precision and longer service life. alleged a minute of price a minute of goods, home, Taiwan, Japan and Euramerican the price of manufacturer of these 3 kinds of chuck and technical content are shown by low to tall permutation. And this among them, taiwan chuck achieved the world’s advanced technology level on reasonable price, the import share of 60% occupies the market that understands it than card to accept degree. After be being used for long to often protect lathe chuck, still can assure good precision, lubricant job becomes important all the more. Incorrect or improper lubricant when will causing low pressure abnormal function, clip holds power abate, clip holds precision undesirable, wear away out of order reach card to live wait for a problem, must lubricate correctly so chuck. Above all, make oil of 2 vulcanization molybdenum at least everyday (color is black) , infiltrate grease chuck is oily inside spill over till grease the aperture inside the face that place claw or chuck is in (inside Kong Bao jacket and) of place of concatenate screw cap, but if chuck is tall,rotate or oil of cutting of many ability in swimming is used at treatment when, need is more and lubricant, beard according to does not decide with the circumstance. Next, exercise cease current affairs comes with wind gun or similar tool surely clean chuck noumenon and slideway face. What should do next is at least every 6 months tear open next chuck to decompose clean, maintain clip claw to slide the face gives completely lubricant, make chuck life grows. And make appliance has oil of antirust effect cutting, precautionary chuck interior is rusty, prevent to chuck rusts and reduce clip to hold power, cause cannot workpiece clamp. Match an appropriate chuck to be able to make with might doubled of numerical control machine tool, manufacturer must measure body choice according to the actual condition of oneself product when the choice, such ability make its produce better effect.