Wave Thread Stress Concentration Graphs

last updated 02/20/2020

These Wave threads have the same shank diameter, but different lengths. One of the defining factors is the angle between the net change in radii and the thread length called the conix angle. Changing the length changes that angle.

These Wave threads have the same shank diameter, but change the shape of their threads over the length of their threads. Specifically the period P1 does not change. The period P2 decreases at a constant rate 1/2 the period width. The amplitude height D1 has no change. D2 doubles its height over the length of the thread. The graphs show the impact of these characteristcs.

It is important to note the P1D1 has a higher centration of stress then the UNC. It is also on the second thread, not the first. The significance is the stress is enclosed between the first and third threads. This support on both sides aids the second thread in resisting the concentrated load more then the UNC thread that only one side. This is why 90% of threads break on the first one.