Clamping jaw assembly and drill chuck

A clamping jaw assembly, comprising a first clamping jaw, the clamping jaw assembly further comprises a second clamping jaw, both the first clamping jaw and the second clamping jaw comprising a screwing section, each screwing section comprising a thread arranged at an outer surface of the screwing section, a clamping section being arranged at a top end of each screwing section, the screwing section being fixedly connected with corresponding clamping section, an inner side of the clamping section of the first clamping jaw comprising a first clamping part, and an inner side of the clamping section of the second clamping jaw comprising a second clamping part matched with the first clamping part,

• wherein
• an arc-shaped groove is arranged at a center of an inner side of the first clamping part;
• symmetrical tooth-like protrusions being respectively arranged at two sides of the arc-shaped groove;
• an elongated groove is arranged at a center of an inner side of the second clamping part, the elongated groove being rectangular, a side wall of the elongated groove being perpendicular to a bottom wall;
• two sides of the elongated groove are both provided with a smooth part, the smooth parts being perpendicular to the side walls of the elongated groove;
• and clasping parts are arranged at two sides of the smooth part.