Abstract: A vise includes a base having a fixed clamp member and a rack member is connected to the base. A movable clamp member is movably connected to the base and a rod extends through a horizontal portion of the movable clamp member. A connection member is mounted to the rod and has two lugs between which a pushing member is pivotally connected. A position member is pivotally connected to the connection member and a second end of the position member is engaged with of the rack member. A head is connected to the rod and located between the two lugs. The head has an inclined surface and an underside of the pushing member is rested on the inclined surface. A pushing surface is defined in an end of the pushing member and is matched with a vertical portion of the movable clamp member. The pushing member prevents the top portion of the movable clamp member from being deformed.