4'' 3-Jaw Self-Centering LatheChuck The 4'' 3-jaw lathe chuck is made ofhigh-strength HT300 material with strong compression resistance andlong service life. It features an internal and external jaw toclamp larger-sized industrial components and a self-centeringfunction to avoid repeated calibration. Outstanding Operating Precision The 3-jaw chuck has a self-centeringfunction and a bevel gear to precisely control the accuracy of theclamped workpiece for precise machining. Bearing tolerance ? 0.05mm / 0.002" ensures the lathe chuck's structural stability and highaccuracy. Adjustable Chuck Jaw We provide you with two types of jaws,internal jaw, and external jaw, capable of clamping larger-sizedindustrial components. You can easily open and close the jaws byrotating the T-shaped key. Easy to Use This chuck consists of a chuck body,movable chuck, and jaw drive with a simple structure. When clampinga work part, the chuck is able to find and hold the center of thepart automatically. All you need to do is install them in thecorrect order. Wide Application Whether you're working in woodworking,metalworking, drilling, or milling, our 3-jaw self-centering lathechuck can meet your requirements for improved machiningefficiencies and increased job flexibility and precision.