A wire clamp for connecting electric wires includes a conducting body having a horizontal portion and a vertical portion in the form of an overturned L. The vertical portion includes an opening adapted to receive the bare end of a wire for clamping and the horizontal portion includes an engagement element adapted to engage an actuating element, such as a screw, for actuating the conducting body in the vertical direction to clamp the wire against a horizontal element. The horizontal portion can include a free end that is folded downward, extending in a vertical direction. The folded free end can interfere with the actuating element causing the actuating element to lock.