A wrench is a type of lever that is used in combination with socket heads, known as "bare nuts". It consists of a metal bar on which the wear square can be moved freely. This square is the end on which the nut itself is mounted for loosening or tightening bolts and nuts. The main function of the wrench is to allow the user to exert a high torque, which is the rotational force needed to loosen very tight or rusted joints. Thanks to the sliding mechanism, the square can be placed in the middle of the bar, giving the tool a T-shape. This position is suitable for fast and symmetrical rotation, for example when loosening an already loosened bolt. If the square is moved to one end of the bar, an L-shaped lever is created, providing maximum leverage to exert the greatest possible force. This variability allows the tool to be adapted to the specific situation, whether force or speed is required.