Heavy Duty Plain Bearing Chucks, K4, 0.18 in-0.8 in Cap., 3JT Female, Key Drive

Features: Fluted sleeve standard on all models except 14451 | Jaws center-ground for absolute straightness and alignment | Jaws specially treated to ensure extended thread life and high gripping surface hardness | One-piece sleeve eliminates crack between driving teeth often found in other designs | Through-hardened sleeve teeth, nose, and keyholes for wear resistance | For portable, bench, or floor mounted power tools | At minimum capacity will hold a No. 60 (.040in/1mm) drill