There is always a trade-off between the potential backout torque you may gain when using some kind of locking feature located on the tapping threads and the clampload you may never realize when the screw is put into tension, because the of the quality of the mating thread that is formed after...
I would like to direct you to www.shakeproof.com and in particular the Tap/R product. The design basically has high relief on two sides of the screw point that transition into a round-bodied thread.
When dealing with castings, the Taptite literature will tell you that a thread engagement...
