That's an excellent question, and it gets to the very heart of why some park benches become community heirlooms while others fall apart in a few seasons. The choice of fastener is absolutely critical—it's the unseen hero of durability. We don't just use "screws and bolts"; we specify a system of hardware designed to fight the elements and constant use.
First and foremost, we use stainless steel bolts, nuts, and washers, typically Grade 304 or the more corrosion-resistant 316 for coastal areas. Steel will rust, but stainless steel resists corrosion, preventing those ugly streaks and, more importantly, maintaining its structural grip for decades.
For structural joints and frame assembly, we rely on hot-dip galvanized steel brackets and connectors. This process coats the steel in a thick layer of zinc, providing a sacrificial layer that fights rust. These heavy-duty brackets are what handle the stress of people leaning back and the constant weight.
We also strategically use locking nuts (like nylon-insert locknuts) and thread-locking adhesive on critical bolts. A park bench is a vibration machine—people sit, shift, and move. These locking mechanisms prevent hardware from gradually shaking loose over thousands of uses, which is a common failure point.
Finally, the philosophy is just as important as the parts. We oversize hardware slightly for a margin of safety, counter-bore holes so bolt heads sit flush and protected, and always pre-drill pilot holes in wood to prevent splitting. The goal is to create a connection that allows the wood to move naturally with moisture and temperature without compromising the joint's integrity.
In short, longevity comes from specifying corrosion-resistant materials like stainless steel and galvanized steel, employing locking mechanisms, and using precise, thoughtful installation techniques. It's an investment in invisible quality that pays off in decades of reliable service.