So it "toe-nailing" with a self tapping screw!
It looks to have a raised thread like a drywall screw.
It seems to be less about the design of the screw, and more about the jig that makes it easy to drill the counter sink hole.
I would think the question about using this to attach bulk heads would be more about using this method than this particular screw.
As for me those screws have no place on a boat...the idea of "toe-nailing" has its place...if used for attaching bulk heads I'd us a lot of screws, SS or bronze.
However, I would prefer other more robust methods that will be easier to plug the holes.
S/V Arctic Lady