I believe that I failed to mention that these are being driven into a blind hole. This, in my oppinion, creates an instance where, as Tmoose stated, the screw is still turning and cutting threads at the same time that it is stretching and being placed in tension.
I have machined a jig and by...
I can see this from both perspectives. On one hand you have the amount of torque to drive a pre-threaded fastener, which uses the standard torque coefficient. On the other hand you have a thread forming fastener that requires added torque to drive, thus the question. Does the preload drop due to...
Can any one tell me an easy way to measure the preload on a small screw. I have a #10 screw used to assemble 2 housing halves. I am looking to switch to a thread forming screw to elliminate the secondary opperation of tapping. The dillima comes from the driving torque of the thread rolling...
