Secure these chucks to the slot-drive tapered spindles on older drills and mud mixers. Their slot-drive design locks these chucks onto your tool, so they won’t slip on the spindle, no matter how often you start, stop, or reverse. They hold bits just as tightly—use the included key to tighten or loosen the jaws. These chucks are built for tough jobs, like drilling through hard materials and mixing thick slurries. For a long life and improved accuracy, they have a one-piece sleeve, center-ground jaws, and hardened wear points. They’re also known as positive-drive drill chucks.

To maximize grip and minimize wobble, choose a chuck where your drill bit diameter falls in the middle of the 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. They grip bits tighter and stay accurate longer than medium duty chucks when under heavy loads.