A torque-adjustable wrench, comprising: a handle; and a bit (10, 10') attached to the handle, the bit (10, 10') including a worm and further comprising: a body comprising a front end and a stationary jaw extending from the front end; a movable jaw movably connected to the front end of the body so that a distance between the jaws (12, 40) is adjustable; and a pointer formed on a side of the movable jaw, characterized in that the handle is equipped with a torque-adjusting mechanism operable to adjust a maximum value of torque to be exerted on a workpiece; multiple color marks (24, 25, 26, 27) are formed on a side of the body, wherein each of the color marks (24, 25, 26, 27) is in a different color and corresponds to one of various sizes of a workpiece, wherein the distance between the jaws (12, 40) is set to be a value corresponding to the size of the workpiece when the pointer is aligned with one of the color marks (24, 25, 26, 27); wherein each color mark (24, 25, 26, 27) further corresponds to a colored region (575, 576, 577, 578) of a torque-indicating unit on the handle, each colored region (575, 576, 577, 578) carrying a number (575A, 576A, 577A, 578A) that represents a corresponding maximum value of torque. a handle; and a bit (10, 10') attached to the handle, the bit (10, 10') including a worm and further comprising: a body comprising a front end and a stationary jaw extending from the front end; a movable jaw movably connected to the front end of the body so that a distance between the jaws (12, 40) is adjustable; and a pointer formed on a side of the movable jaw, characterized in that the handle is equipped with a torque-adjusting mechanism operable to adjust a maximum value of torque to be exerted on a workpiece; multiple color marks (24, 25, 26, 27) are formed on a side of the body, wherein each of the color marks (24, 25, 26, 27) is in a different color and corresponds to one of various sizes of a workpiece, wherein the distance between the jaws (12, 40) is set to be a value corresponding to the size of the workpiece when the pointer is aligned with one of the color marks (24, 25, 26, 27); wherein each color mark (24, 25, 26, 27) further corresponds to a colored region (575, 576, 577, 578) of a torque-indicating unit on the handle, each colored region (575, 576, 577, 578) carrying a number (575A, 576A, 577A, 578A) that represents a corresponding maximum value of torque. a body comprising a front end and a stationary jaw extending from the front end; a movable jaw movably connected to the front end of the body so that a distance between the jaws (12, 40) is adjustable; and a pointer formed on a side of the movable jaw, characterized in that the handle is equipped with a torque-adjusting mechanism operable to adjust a maximum value of torque to be exerted on a workpiece; multiple color marks (24, 25, 26, 27) are formed on a side of the body, wherein each of the color marks (24, 25, 26, 27) is in a different color and corresponds to one of various sizes of a workpiece, wherein the distance between the jaws (12, 40) is set to be a value corresponding to the size of the workpiece when the pointer is aligned with one of the color marks (24, 25, 26, 27); wherein each color mark (24, 25, 26, 27) further corresponds to a colored region (575, 576, 577, 578) of a torque-indicating unit on the handle, each colored region (575, 576, 577, 578) carrying a number (575A, 576A, 577A, 578A) that represents a corresponding maximum value of torque.