Secure bits into your drill press, milling machine, or lathe. These chucks are keyed, so they grip bits tightly to prevent slipping under heavy loads. Use the included key to tighten and loosen the jaws. Attach these chucks to your machine with a Jacobs taper arbor. To maximize grip and minimize runout, choose a chuck where your drill bit diameter falls in the middle of the bit shank size range.

Heavy duty chucks give you the rigidity and heft needed for high-torque drilling in hardened metal. Their extra mass means they resist vibration and fluctuating cutting forces to keep your bit stable. While they share all of the same features as medium duty chucks—one-piece sleeve, center-ground jaws, and hardened wear points—they grip bits tighter and stay accurate longer under heavy loads.

Jacobs chucks are the most widely used drill chucks. Those with a locking collar replace your older Jacobs model 633C chuck. The 1 1/16"-20 thread on the locking collar matches older drill presses.