TLS is a preset torque limiting screwdriver (internally adjustable). The torque screwdriver is built with a cam-over design that prevents a fastener or bolt from being over-tightened. When the torque screwdriver reaches the preset torque value, the internal mechanism disengages from the drive, thus limiting the torque applied. Using a quality torque screwdriver ensures that proper torque is applied and maintains requirements associated with ISO quality standards.

The preferred and certified ranges of these tools is in accordance with the requirements of ISO 6789 (+/- 6% of indicated setting).