Last year when I built the Gazebo (http://countryplans.com/smf/index.php?topic=2335.msg32610#msg32610) I set up a small experiment with ACQ and different fasteners.
I used ACQ .40 PT as the test wood.
Test fasteners chosen were -
1. hot dipped 8D galvanized nails
2. Bostitch old 8D electro galvanized nails
3. Bostitch new 8D electro galvanized, the ones the box states are okay with all PT wood
4. roofing nails, electro galvanized
5. coated deck screws, gray color
6. regular bright common 8D nails
Here's what I found, one year after the fasteners were inserted. The wood was sitting in the gazebo, behind the chairs, against the wall. Mostly dry conditions although it may have gotten rained on at some time. Several months of the year hve high humidity, the rest of the year the humidity gets quite low.
1. no visible change
2. faint trace of corrosion in specks here and there
3. no visible change
4. faint trace of corrosion in specks here and there
5. no visible change
6. rusty, rusty, rusty