The torque screwdriver is pre-set to the required torque value of the application. A preset torque screwdriver does not feature an external adjustment scale. These tools have an internal adjustment mechanism for setting the torque value and must be preset internally using a hex key and a torque analyzer or torque sensor. However, if the torque specification changes or a new project requires a different torque setting, the preset torque screwdriver is still flexible enough that a new torque setting can be set internally using a torque tester.
The preferred and certified ranges of these tools is in accordance with the requirements of ISO 6789 (+/- 6% of indicated setting).