I need to bolt a bit of flat steel to the top side of a length of box section.
How can I do this?
Because it is fully enclosed I can not get a nut inside. It is going to be about 4-5mm thickness in wall section, maybe I can drill out some holes and tap them? Will 4-5mm be enough steel for there to be enough grip if I tap the holes with threads?
Any ideas on what I can do?