The self-centering lathe chuck is composed of a strong zinc alloy body and steel jaws so that it can withstand harsh working environments. It features a wide clamping range and high accurate. So you can deal with a variety of materials after fastening it. Features: The lathe chuck body is made of fine quality zinc alloy. The surface is nicely ground with a nice radius on all external edges. Efficiently push the material to be processed from all directions simultaneously until it is held tightly. The lathe chuck of the tolerance ≤0.002 inch works with few vibrations, ensuring accurate finished parts. It is easy for you to adjust the jaws by scrolling the chuckkey. Quicker installation leaves more time for work. The chuck has internal and external jaws. This chuck has a large clamping range and is suitable for clamping a variety of industrial parts. The manual self-centering chuck is compact and convenient, and it is the perfect choice for your lathe machine, grinding machines, or milling machines. Specifications: Type: 3 jaws, 4 jaws (optional) Connecting shaft: 3.17mm, 5mm, 8mm (optional) Material: zinc alloy+stainless steel Chunk thread diameter: 12mm Chunk threadpitch: 1mm Chunk diameter: approx. 50mm / 2.0in Package size: 90 * 70 * 45mm / 3.5 * 2.8 * 1.8in Package weight: 226g / 8.0ounce Packing List: 1 * Chunk 1 * Connecting Shaft 2 * Screws 1 * Wrench for Chunk 1 * Wrench for Connecting Shaft Screws