When the horrible heat breaks, I need to put a new wood deck on my old
truck. I found the steel frame on the dump bed to be really rusted and
replaced most of the cross members with a heavier channel iron than
original.

What fastener is best to put 2 x 12s on to a steel frame. I looked for
self tapping screws and didn't find anything rated to do the four inch
channel iron. Maybe I need to look more.

Suggestions?

Karl