Abstract: A drill chuck has an externally toothed body, a plurality of jaws, and a tightening ring rotatable on the body in tightening and loosening directions. Screwthreads between the tightening ring and the jaws move the jaws radially. A pawl engageable with the teeth is angularly fixed on the tightening ring and can shift between a retaining position engaging the teeth and a freeing position disengaged from the teeth. An adjustment sleeve is limitedly angularly displaceable on the body relative to the tightening ring between a locked end position and an unlocked end position. A cam on the adjustment sleeve can displace the pawl into the retaining position when the adjustment sleeve is in the locked end position and into the freeing position when the adjustment sleeve is in the unlocked end position. A locking part can engage the pawl in the retaining position thereof to lock the chuck.