Feature: 1. FOR LATHE AND MILLING MACHINE: Clamping collet chuck can be mounted to the back plate of your choice for use on a lathe, also suitable as a chuck on milling machine 2. DURABLE CARBON STEEL: Made of excellent carbon steel material, possess strong antioxidant capacity and high hardness 3. FOR CNC ENGRAVER: Clamping collet chuck is suitable for CNC milling machine turning tool engraving machine, not easy to slip, very stable 4. GUARANTEED QUALITY: Made after standard production, so that your products can be processed better, more efficiently, and more durable 5. GOOD CLAMPING FORCE: Clamping nut holder possess stable structure, excellent performance and long service life, you can use with confidence Specification: Item Type: Clamping Collet Chuck Model: ER40(7 holes) Size: Diameter: Approx. 80mm / 3.15in Accuracy: 0.005 Material: Carbon steel. Package List: 1 x Clamping Collet Chuck Note: Before inserting the collet chuck, the collet must be assembled into the collet chuck nut.