1、High Accuracy: This integrated self tightening drill chuck has a clamping range of 1/32in to 1/2in (1mm to 13mm) shanks with an accuracy of 0.003in to 0.005in. 2、Excellent 40cr Alloy Steel Material: This integrated drill chuck is made of excellent 40cr alloy steel material, which has better wear resistance and more stable performance. 3、Polished Finish Surface: The surface of this self tightening chuck has been polished to a very flat and sleek finish and is shiny and aesthetically pleasing. 4、Quenched And Hardened: This drill chuck tool holder is quenched and hardened to improve hardness and good overall mechanical properties. 5、Wide Application: This keyless hand drill chuck has a wide range of applications and can be used on CNC machine tools and machining centers, mainly for drilling and milling machines for drilling use.