dave wrote:
looking for a mechanical method to attach sheet metal to thick steel
without welding, drilling, or tapping. preferably leaving behind
tamper-proof (or 'nearly so') heads. what's a guy ask for when he wants
a self-drilling, self-threading machine bolts that have heads on them
that snap off after a certain torque is reached?

alternately, are there bolts made (just like above) except they'd have
TWO heads 'stacked' in an hourglass-like config, so that I'd have to CUT
their uppper heads off with my cutoff wheel, manually? (which'd be
perfectly fine with me)

alternately, what's the biggest diameter pop-rivet that can be 'manually
popped'? I mean like for which a tool that's "fairly readily available"
new -or- used?

thanks guys,

toolie

Another possible way to get there is to use Robertson screws . Once
installed you set a small piece of lead shot in the hole and tap it in
with a hammer . I know some commercial installations are doing this . It
is fast simple and cheap . Luck
Ken Cutt