On 26 Dec 2006 04:05:13 -0800, "mhorowit" wrote:

I see mention of "PK" screws. Can someone point me to an illustration?

At http://www.aircraftspruce.com/menus/...talscrews.html is a
Truss Head Type 'A' sheet metal screw, which is what I'm visualizing;
is that it? - MIke

without checking the ref it sounds correct.
pk refers to the original makers brand. ie Parker Kalon.
they are a standard aviation sheet metal screw used with tinnerman
(another brand) sheet metal fasteners.