The TA Series tools use a combination of torque for snugging and angle for final installation. Each of these functions require calibration at least annually. A quick way to verify snug torque is to use one of our Digital Torque Meters. The DTM can be easily attached to the TA Series Wrenches and will produce a real time torque that is displayed on the digital read out. If the reading on the DTM is close to the rated output of the tool you know your calibration is good.