Description: For those that prefer traditional keyed drill chucks, these chucks offer precision and nearly unlimited mechanical advantage for tightening and loosening drill bits and tooling. These 1/32" - 5/8" JT3 Taper drill chucks have knurled grips and the chuck key is included. Specifications: 1/32" - 5/8" JT3 Knurled Grips Chuck Key Included Arbor hole tapers from .80 inches at the opening (bottom of chuck) to .78 inches 1/2" down into the arbor hole. This gives a good fit profile for getting the correct chuck for your drill press