In ,
notbob typed:
The Daring Dufas writes:


Most guys in the trades call them Tek screws.

http://www.imperialinc.com/grp076.shtml

I see many different types, there. Thanks for that.

I guess I should have been a little more specific, in that
I was looking for a self-tapping screw that would easily
penetrate soft or low-carbon steel, like the one's I used
on the Limey motorcycle frame. Is that a special type, or
do they all do that? I'm looking to use the screws to
punch through and lock up the louvre adj linkage on a
forced air heat register, which is stamped steel. Thnx.

nb

There are different types of screws: The self-drilling and self-tapping.
One simply brings the point of the screw to a fine point with the threads
going all the way to the end. They're good for sheet metal or most sheet
products.
BTW, your motorcycle or whatever it was is likely to be soft steel; it
has to have five to it in order to not crack or break upon hard hits on the
screw during riding. I know the frames on Harleys and Hondas are soft steel,
depending on what part you'\re looking at; like the frame itself, front
fork, etc..

The other type, the threads don't go all the way to the point. However, the
point is shaped almost like drill bit and some are fluted, to pull the
debris out, within reason. The length of the drill-looking part is the depth
of steel max it can be used on. All kinds of sizings are available.
See http://www.imperialinc.com/items.asp?item=8901330 for a sample pic.
Unless I'm doing sheet metal type stuff, I like those the best because it
pre-drills the hole for istelf all the way in, the larger threads providing
the actual holding power like any other screw.

Either type should work for you.

HTH,

Twayne`