Sure I've seen them. The weakest point in a sheet metal screw is the
diameter just under the head. Any strain will tear the sheet metal.
There are screws with a shoulder machined on the head so it will fit
into a larger diameter hole in the sheet metal being fastened. The
shoulder distributes the stress on the metal [skin] over a larger area
I believe they are used in the aircraft industry mostly to fasten Al
panels.
I wouldn't lnow a source for them, but they are probably described in
the AN military specs.
Bugs