Item Type: Collet Chuck Holder Material: 40cr alloy steel Model: NT30 ER25 Rear Drawing Thread: M12 Tail Hole Diameter: Approx. 12mm / 0.47in Structure Type: Integral Accuracy: 0.003 Scope of Application: CNC machining centers, engraving machines, fine engraving machines and other high speed machines Package List 1 x Collet Chuck Holder 1 x Wrench 1WEAR RESISTANT ALLOY STEEL: Adopt good quality 40cr alloy steel material, possess better wear resistance and more stable performance 2HIGH HARDNESS AND TOUGHNESS: Vacuum quenching treatment can realize carbon oxygen co infiltration to improve hardness of tool. Blackening treatment bring high surface hardness, strong fatigue resistance and high wear resistance, maintain the strength and toughness of low carbon steel in the core after quenching, so that the handle can withstand a certain impact with load, more durable 3PROTECTIVE FULLY GROUND: The shank is fully ground as a whole, effectively protecting the connection of the taper hole of the power head 4HIGH CENTERING ACCURACY: The surface is brightly ground, beautiful and elegant; the shank hole is finely ground, and the centering accuracy is high 5DISPERSED PRESSURE: The holder is integrally formed, with good structural rigidity. When used, the pressure is dispersed on the accurate needle rollers of the cage, which is suitable for large cutting amount processing