Button Head Double Square 3/16-10 x 1" Exterior Metal Tek Screw
This is the screw that most trailer manufacturers such as Haulmark and Pace use to attach the exterior metal to the steel studs. We use them for many many applications.
Zinc plated to resist rusting.
They are self-tapping meaning no pre-drilling is required to install them into metal. I even used them to attach the legs of my daughter's trampoline together so it wouldn't fall apart every time I had to move it to mow underneath it!
We have the drive bit for them and they are also available in 1/2" and 3/4" lengths.
Threads Per Inch: 10