spuare or hexlobular threads once harden in 410ss or carbon
steel show remarkable tapping/threading capacity that tap
thick metal sheet into a threaded nut. In other words, as
long as there is a pre-drilled hole, these threads will form
the threads in the hole for as thick as the sheet. This is
what we meant by genuine self-tapping thread. It simply taps
and forms threads without chips and dusts as long as the thread
and the driven metal. Normally, the conventional round thread
will tap only 2-3mm at the most before the threads start to
collapse, not with the spuare and hexlobular threads.
have used this unipue tapping feature on self-drilling screw.
As a result, a#3 drill point for instance now performs lide
a#4 or even #5 point. A standard #3 point with the conventional
round sheet metal threads normally drills 2-3 mm steel sheet
only, with these threads, it drills well above 5mm.
Sincethese threads simply cut into the metal
instead of frocing into it, you do away with the prethreading
process. There is a much tighter gripping and holding power