“What is my Nut Factor, K?” I get this question often and the honest answer is that sometimes I don’t know.
There is not a K table for every bolted flange assembly combination and all the math in the world is not a replacement for real-world testing. I use the BoltSafe Load Measuring Systems to help me find the Nut Factor, K for critical joints. By slowly dialing my torque wrench to specific values and keeping the Selected Assembly Bolt Stress, Sbsel constant, I can find the Nut Factor, K for just about any bolt/nut/washer/lubricant combination.
The Nut Factor, K has a huge impact on the Assembly Bolt Torque, Tb so any uncertainty can negatively affect your bolted joint assembly. As a matter of fact, junk K values will result in junk Assembly Bolt Torque, Tb values. Testing for the actual K factor for your custom bolted joint assemblies is the best way to ensure leak-free joints.
