scott wrote:
I recently began a constructing a swing set/fort for the kids. The
lumber is ACQ treated. I followed the advice of the salesman at
Lowe's and HD and picked up carriage bolts, washers, and lock nuts.
These were a mix of electroplated zinc coated as well as galvanized.
None of the home centers state how thick the coating is on their
fasteners.

I assembled a portion of the playset, and a week later I needed to
partially disassemble it to make a modification. I was shocked to
find the portion of the carriage bolt and washer which had been in
contact with the wood had much of its coating eaten away and was
turning orange.

You have two choices. Stainless steel. or hot double-dipped galvanized.
Those are the two options that
ACQ p.t. wood makers recommend.