How do we define breakaway and prevailing torque?
When we apply a threadlocker to a bolt and finger tighten a nut down, we let this sit for 24 hours and allow it to fully cure. We then take a torque wrench and break the bond. The initial reading on the unseated assembly is the breakaway value (remember, this is not torqued to a specified value such as 100 in lbs). This shows us the strength of the threadlocker alone. They then continue turning this and the average of four quarter turns provides us with our prevailing torque value. This shows us how much friction or drag is left to continue turning the nut. If for example, on the other hand, we torque the assembly down to 100 in lbs, and we use a threadlocker with a breakaway of 50 in lbs, the breakloose value initially on this seated assembly is 150 in lbs (100 + 50). The difference between what you torque this down to (100 in lbs) and what you breakloose at, (150 in lbs) is 50 in lbs and this is referred to as torque augmentation. The main function of any threadlocker is to maintain your torque. It's been determined that over time due to various factors such as vibration and side sliding, that you lose up to 30% of your on torque. The goal is to choose a suitable threadlocker that provides a breakaway value equivalent to 30% of what you torque the assembly to in order to maintain your torque over time.