A torque wrench is a precision tool used to measure the force applied to a fastener while tightening. A visual or audio indicator signals when you reach the torque force so you know when to stop applying pressure. This prevents overtightening a bolt, which can cause damage to the fastener, or undertightening, which can result in potential weakness to the item you are attaching or assembling.
In some instances, such as within the auto industry, tightening is also measured by the angle method. Measuring a torque angle is an accurate final check for the tension applied to a bolt when tightened. An angular torque wrench electronically measures both torque force and angle rotation. This one tool eliminates the need for using an angle gauge or protractor together with the torque wrench, and it's ultimately more accurate and faster.
An angular torque wrench is often used for automotive mechanical applications, when both torque force and defined angle measurements are specified. Torque angle specifications must be determined, as well as maximum torque force, for the bolt you are fastening. A digital readout displays both torque and angle, which can be preset. Specific angle measurements are used to determine that the bolts are equally fastened at the required angle degree. It's especially important for mechanics to double check the fastenings.
The most accurate way to tighten bolts is to work gradually. Tighten all the bolts in rotating sequence, using a third of the force needed each time. The final measurement includes the degree of angle rotation according to the specified setting for the fastener. This is the final test for strength and reliability.