How do you calculate bolt torque?

The widely recognized engineering formula, T= K x D x P (to be explained later in this article), was used to provide the chart’s values, but it must be understood that every bolted joint is unique and the optimum tightening torque should be determined for each application by careful experimentation.

What is a torque to yield bolt?

What is a torque-to-yield bolt? It is a one-time-use fastener that is designed to stretch during the torquing process (installation). Because of this stretching, the integrity of the bolt is compromised. These bolts cannot and should not be reused due to the stress caused to the bolt during its first installation.

How do you use torque to yield?

How is nut torque calculated?

The following equation estimates the amount of torque required to achieve a predetermined clamp force if the diameter of the bolt is known. T=torque, F=force, D=diameter, and K=nut factor*. *In this equation the nut factor is often assumed to be 0.2. It can widely vary as a result of many factors.

How do you calculate the yield strength of a bolt?

Yield Strength

Take the minimum yield in psi of the ASTM grade (see our Strength Requirements by Grade Chart for this value), multiplied by the stress area of the specific diameter (see our Thread Pitch Chart). This formula will give you the ultimate yield strength of that size and grade of bolt.

What happens if you over torque a torque-to-yield bolt?

If the bolt is over-torqued and stretched beyond its limit, this exceeds its yield strength which means it can no longer maintain the needed clamp load and must be replaced. … Finally, using a breaker bar, the bolt is tightened, which moves the dial to the specified angle – hence the term torque-angle.