Comparison of Electric and Mechanical Torque Wrenches

A common question asked is how do electric motors with torque control compare with mechanical torque wrenches. An article "Comparison of Torque Measurements and Clinical Handling of Various Surgical Motors" was published in the International Journal of Oral & Maxillofacial Implants, Vol. 24, Number 3, 2009. This study measured the deviation of several surgical motors to the selected torque settings. The study concluded that the average percentage of deviation for all selected torque settings with the surgical motors was -20.5% to +54.6%. This deviation is substantially larger than the deviation for mechanical torque wrenches which are from -10% to +10%. Since accuracy and repeatability is essential in torque control, it can be concluded that the mechanical style of torque wrench is the better option.