1The chuck is made of spring steel, hardened and ground, with high accuracy, and accurate internal thread. 25C square smooth chuck for fixing workpieces on lathes or other machine tools. 3The collet is used to hold metals, plastics, carbides, graphite and ceramics in industrial manufacturing applications. 4Collets are also used in applications such as the manufacture of metal and wood components, semiconductor manufacturing and processes. 5Fine workmanship, good elasticity, high hardness and strong wear resistance.