Description You'll get better concentricity and more consistent clamping force with this 4-jaw self-centering lathe chuck. It is made of cast iron and steel with high strength and toughness and is available in both internal and external jaws, giving better control over the chuck to improve the machining accuracy of the chuck. It is an ideal accessory for machine tool machining! Key Features Built to Last: Made of cast iron and steel, this product is rust-resistant, wear-resistant, and durable, ensuring your long-term use. Self-centering Function: The auto-centering mechanism can automatically adjust according to the geometric center of the workpiece without complex measurement and adjustment, reducing human error and making it easy to operate. High Precision: Four-jaw self-centering chuck design ensures high-precision positioning of the workpiece in axial and radial directions, reduces machining errors and ensures machining accuracy and finished product quality. Multiple Adaptability: