Features 1、FINE PROCESSING: Vacuum quenching treatment can realize carbon oxycarburizing to improve the hardness, and fine grinding can increase the anti corrosion ability. 2、INTEGRATED DESIGN: The inner and outer cone are finely ground, the chuck and the body inner cone are formed at one time, with uniform strength and high concentricity. 3、SOLID STRUCTURE: The back pull clamping design of the handle, and the design of tightening the tie rod screw can prevent the handle from falling off. 4、40CR ALLOY STEEL: Made of excellent 40Cr alloy steel material, has high hardness and wear resistance, not easy to deform or corrode for a long time. 5、WIDE APPLICATION: Widely used in CNC machining centers, engraving machines and other high speed processing machines, which is efficient and durable. Specification Item Type: Chuck Tool Holder Model: NT30 ER40 Material: 40Cr Alloy Steel Drawbar Thread: M12 Tail Aperture: Approx. 12mm / 0.5in Structure Type: Integral Accuracy: 0.003 Scope of Application: CNC machining center, engraving machine and other high speed machines Package List 1 x Chuck Tool Holder 1 x ER40 Wrench