The standard option is hot-dipped galvanized nails, which provide more corrosion-resistance than electro-galvanized or hot-galvanized materials. The most reliable material for pressure-treated wood is stainless steel. Use 6-d (2-inch) rink shank nails to fasten pickets and infill boards.
Choose hot-dipped galvanized number 304 stainless steel nails that are about 1 1/4 inches longer than the thickness of your cedar fencing. The Western Red Cedar Association (WRCA) recommends these nails for your fencing jobs, since other types of nails will rust quickly and leave black streaks below each nail point.