This is a picture of what we're talking about.
re: countersinking--I would be a bit hesitant, just because the plates are only (heh, only...) 3/16" thick. Schlud's idea seems pretty reasonable though, but I think I'm having a hard time visualizing rhombus's idea in action. (Even with the diagram...
)
I haven't had a problem snapping them since I switched to grade 8 hardware, btw...the heads get a bit mangled but I can still get a socket on them. Might just be I haven't hit them right though.