A woodworking vice including a frame, the frame has a clamp assembly and a connection rod matching with the assembly, and a front end of the rod is hinged to the frame. A rear end of the rod is provided with an extending frame extending upwardly, a front end of a locking member is hinged to an upper end of the extending frame, and a middle portion of a rocker is hinged to the upper end of the extending frame and is located below the locking member. The locking member is provided with a cooperation hole, and the locking member is equipped with a torsion spring making the locking member have a tendency of rotating clockwise. A rear portion of the frame is provided with a locking rod extending downwardly, the rod passes through the cooperation hole, and a rear end of the rocker is matched with the locking member.

A master jaw assembly for an engineering vise is provided by the invention. The master jaw assembly comprises a master jaw having a groove formed in its side wall face, and a detachable jaw having a dovetailed rib projecting from its side wall face so that the soft jaw may be attached to the master jaw by frontally inserting the dovetailed rib into the groove with minimal loosening of the hold-down nuts in the master jaw. A special hold-down nut used to secure the dovetailed rib of the detachable jaw inside the groove of the master jaw has a substantially longer base edge compared with its top edge to provide increased securing force. The master jaw also features an adjustable reference stop plate attached to the end of the master jaw that may be moved to its engagement position when needed to engage the edge of or interior niche in the detachable jaw to ensure that the detachable jaw is attached to the master jaw in precisely accurate alignment on a repeatable basis.