OK as I have said before I'm learning. Every day I learn something new!

When they assemble trucks are things such as body brackets pre-threaded? For
example I'm working trying to install the rear mud flaps. Part of the
process is to remove the bolt located just behind the rear wheel well under
the rolled edge of the body panel. This bolt holds the lower side panel to a
support type rod/bracket to make things rigid. Mud flap instructions show
there being a nut but not on my truck. The bracket is the nut on my 2006. On
both sides the bolts were stripped before I even tried to disassemble. So I
went and bought a tap while I was buying new bolts. I used the tap to chase
the threads in the brackets. Instead of just chasing threads it felt like I
was cutting original threads.

So the question I have is when this was assembled at the factory did the
rod.bracket have threads before they assembled? Or is the body bolt supposed
to be a self threading bolt? I see where the end of it is special to help
with finding the hole during assembly. And since both were in such bad shape
it isn't just coincidence. Now that I have actually taped new clean threads
the new body bolt go in and out like they were made for each other.

I'm thinking for the factory to pre-thread the bracket cost money. So
instead the assembly person has an air driven tool to speed up the effort.
The bolt is placed in tool, end of bolt helps them find the hole, air tool
has enough torque to cut threads as it installs the bolt, and provided you
never take it apart to put mud flaps on it will stay together for ever. But
if you try to remove the bolts sometimes it comes out fine and other times
you get what I got which is a chance to gain experience and learn something
new.

I do appreciate all input! Like I said I can't learn unless I ask questions
and work on stuff.