14N Ball Bearing Chuck1-piece fluted sleeve construction. Ball trust bearing reduces friction in chuck closing mechanism. Through-hardened sleeve teeth, nose, and keyholes for wear resistant. Maximizes gripping force and drilling accuracy. Treated to ensure thread life and high gripping surface hardness. Jaws center-ground for absolute straightness and alignment. For heavy-duty, close tolerance production drilling. For production drilling equipment, jig borers, milling machines, lathes, and radials. Bit/Blade Mounting Size: 0.040 in [Min], 1/2 in [Max]; Capacity: 0.040 in (mild steel) [Min], 1/2 in (mild steel) [Max]; Finish: Fluted Sleeve; Housing Diam: 2.400 in; Key Size: K3; Mechanism: Ball Bearing; Mounting: Jacobs 3JT Female; Overall Length: 2.970 in [Min], 3.880 in [Max]; Type: Keyed; Weight: 38 oz.