Overmaximum Pitch Diameter for Internal .7500 UNJF 16 Thread

[afreedman3]

I am having a problem analyzing a threaded connection.

A boss is threaded as .7500 UNFJ 16 3B. But when the suppliers made the part the pitch and major diameters of this threaded hole are over their maximum as specified in AS8879.

I know the final torque for which the piece that goes into the boss is torqued. I can get an approximate clamping load from the data the company has. I also know the material of both the internal threads and its' mating part. I have looked through a couple of FED-STD's but am unsure of where to start my analysis.

My question is what do you all think is the best way to begin the analysis. I want to know that under the clamping load the internal threads will not be damaged or stripped.

I do not have any data on the internal thread pitch other than what it is supposed to be.

 

[Screwman1]

You can pull out your copy of Bickford or you should be able to use the calculations in this link:

http://www.engineersedge.com/fastener_thread_menu.shtml

If you are trying to seal, then clamp load or torque is a poor indicator of a sealed joint.