I was tired of taping holes in the prints that I was making so I decided to go out and get some self taping screws. I did some research and came across these http://www.microfasteners.com/lpp0206-2-x-3-8-thread-forming-screws-trilobular-for-plastic.html screws.

I have never heard of Trilobular screws before and they are claimed to be specific for soft material such as plastics. I rolled the dice and picked some up.

Drum roll please …….

They work great. They have great holding strength (not imperially tested). They screw in fine and do not seem to cause any issue with repeated screwing and unscrewing. I did need to beef up my screw holes though. I previously had a 6mm cylinder with an 2.26mm hole (I am using a #4 screw) in the middle as a standoff. I found that this seem to have some deformities when the screw was inserted. I increased the cylinder to 8mm and it was much better. I would guess I can do some tests to compare the difference between tapped/machine screws vs. these Trilobular screws but I can tell you that the time saving eliminating the need for tapping is great.