Hand-tight drill chuck

The utility model provides a hand-tight drill chuck which comprises a rotating sleeve, a drill body, a nut, a clamping jaw and a bearing, the bearing comprises a circle of steel balls and a steel ball plastic retainer, a steel ball clamping and pushing structure depending on backward thrust borne by the nut is formed between the nut and a nut supporting structure, and when the drill chuck is in a clamping jaw clamping state, the steel ball clamping and pushing structure is clamped by the clamping jaw. The bearing steel balls can be pushed outwards through the backward thrust applied to the nut; the steel ball plastic retainer is in clearance fit with the rotary sleeve, friction protrusions are arranged on the outer side face of the steel ball plastic retainer, when the drill chuck is in a clamping jaw clamping state, the steel ball plastic retainer deforms outwards due to outward pushing of the steel balls and is combined with the rotary sleeve, and when the drill chuck is in a clamping jaw loosening state, t