"Ignoramus20962" wrote in message
...

SNIP
.. Turned out that I had a bunch of
| nice 10-32 aluminum screws, including some amusing ones with the hole
| for allen wrenches on the SHARP end, and flat (no slot) conical head.
SNIP

Look like this? http://www.hi-shear.com/fastener_hl_stds.htm
They aren't screws. Technically, I think they're called pins. Hi-shear
fasteners, made by Huck, Hi-lok, and others I can't remember. Made to go in
an interference fit hole. In a nutshell, drill a perfect hole of the size
determined by the specs you work to, drive the fastener in, and install a
special nut. The nut selection depends on the fastener material and
structure material. One kind has a hex head that snaps off when you reach
the correct torque, the other resembles a nut and runs down with a special
torquing tool, and in tight spots you can use another nut common in
aviation. Very special installation instructions, and I really like 'em.
Because of the interference fit, the hole will likely never fatigue and
start cracking out, and the high strength means little fasteners can hold a
lot, but then when you see rows of 1/2" and bigger ones holding widebody jet
wings on, you realize how strong they have to be!
The killer on these comes to removal. The hex end holds it from
spinning, should it be so inclined, during rundown and nut removal. To get
the shear type nuts off, it pretty much looks like a split nut cutter or
evil looking pair of pliers. Really easy to screw up getting them out, and
usually you'll have to go oversized when you replace them anyway.