Description: This collet is made of high quality steel for milling lathe tool and work-holding engraving machine. ER straight rod type collet extension handle body is relatively long, suitable for deep hole processing. The nut can be directly tightened to provide a powerful clamping force. This collet can reduce costs, improve efficiency and would be a good replacement part for your old one. Features: This motor shaft collet is made of high quality steel material, straight shank with clamping nut to be tightened. Extension rod diameter and the other parts are precision ground to eliminate unbalance, increase safety when cutting. Straight extended shank fits for deep processing, meeting the needs of extending the depth of processing. Collet is well packed in a protective container with label for safe transportation and storage. It is widely used in boring, milling, drilling, tapping, grinding and other processing. Specifications: Type: ER11A-8mm Material: Steel Height: 40mm / 1.57" Shaft Diameter: 16mm / 0.63" Shaft Inner Diameter: 8mm0.02mm / 0.31" Nut Diameter: 19mm / 7.48" Nut Inner Diameter: 9mm / 3.54" Package Includes: 1 x Collet Note: Please allow 1-2mm error due to manual measurement. Thanks for your understanding.