Screws: Number Of Turns Engagement For Full Strength?

On Sep 8, 12:42 pm, A Muzi wrote:
"jim beam" wrote
need more info - barrel-shaped piece of /what/? in what application?
Jambo wrote:
As if you'd know, ****tard.

Without regard to the merits I have never seen nor heard that word
outside r.b.t.
--
Andrew Muziwww.yellowjersey.org
Open every day since 1 April, 1971

That is one that I've heard from my son about a year ago. I thought
that was a pretty funny insult and congratulated him for his
creativity, and so did my wife. Then, my step daughter informed me
that it was a k-12 standard now.

Andres

wrote:

Chalo Colina writes:
To answer your original question, in commercial fasteners the rule
of thumb is that maximum holding strength achieved at 7 threads of
engagement.
Hardly any machine nuts contain so many threads. Some, like normal
#10-32 nuts, only have four threads in them.

I think you exaggerate. Four threads would make that 10-32 screw an
eighth of an inch long, short screws having threads over their full
length. 4 x 0.03125" = 0.125" the screw major diameter being 0.190".
That four threads fully engaged will suffice, however, is shown by the
size of a matching 10-32 nut. They are nearly identical with an
M5 x 0.8 thread.

Standard #10-32 nuts are 3/8" across flats and only 1/8" thick. I
think that thickness is in common with #6-32 and #8-32 nuts as well.
That's four threads. M5 nuts are 8mm across flats and 4mm thick, for
five threads.

Like all finished nuts, they are chamfered slightly at the opening, so
their actual number of thread turns is less than that implied by the
thread pitch and nut length.

Chalo