Hold collets tightly in CNC machines with dual-contact CAT taper spindles for milling, drilling, and routing. These chucks contact both the taper and spindle face for a more rigid hold than standard chucks. The added rigidity improves accuracy and surface finish while reducing vibration. Made from high-grade nickel chrome-moly steel, these chucks remain stable and accurate while resisting wear—even at high speeds. They’re balanced to G 2.5, further reducing vibration to extend the life of your collets, bits, and spindle. Precision ground to the industry standard AT3 tolerance, these chucks maintain a secure fit that minimizes runout in your machine spindle. They meet ASME standards for CAT spindles to ensure compatibility.

While these chucks are designed for Big-Plus and other dual-contact CAT spindles, they can also be used in standard CAT spindles, just without the added rigidity of the dual contact.

Internal threads on the shank let you attach a retention knob, so you can connect these chucks to your machine’s drawbar system. Insert your collet and tighten the nut to clamp your tool in place. They have a collet stop screw that sets the tool depth in the chuck for consistent, repeatable performance when you change tools. An RFID chip hole holds a small RFID tag for automatic tool identification and tracking. These chucks can deliver coolant to your tool’s cutting edge to clear chips and extend tool life. If you have a through-spindle coolant (TSC) machine, pair them with an ER coolant control collet for the best results.

To maximize grip and minimize runout, choose a chuck where your bit diameter falls in the middle of the bit shank size range.