On Mon, 25 Feb 2008 23:18:25 GMT, John Doe
wrote:

Christopher Tidy wrote:

John Doe wrote:

snip

I need more strength than just enough to thread the machine screw
through a correctly tapped and cleaned hole. If the screw is
going to break so easily, it probably won't hold the pieces
together either. That's my problem.

You shouldn't be breaking even the poorest screws just threading
them into a tapped hole without tightening them. Something is
seriously wrong here. Either that or you're trolling :-).

Like by ignoring the question and for some strange reason insisting
that threading a machine screw into a properly tapped hole is the
only valid application for a machine screw. Plastic screws into
properly tapped holes. Threading screws into a hole is not the end
objective. The objective is to keep the pieces together. I can tell
that the bolts aren't strong enough, that's why I ask for better.

Any steel screw will have greater strength than the aluminum they are
threaded into. If you are twisting the head off I'd agree with
previous posters that there's a problem with the threads in the
aluminum or that you are over toqueing the screw.