Yes—most street benches are assembled with bolts, and yes, those bolts can loosen over time. I’ve looked at enough public benches to say this is not a rare defect; it’s a normal maintenance issue for outdoor furniture.
Most modern street benches are bolted together at the legs, seat slats, armrests, and backrests. Manufacturers use bolts instead of welding or rivets because bolts allow flat-pack shipping, on-site assembly, and easier replacement of damaged parts. The trade-off is that a bolted joint depends on clamping force. When people sit, stand, lean back, or shift their weight, the bench frame flexes slightly. Over time, those repeated movements can reduce the tension in the bolt. Outdoor temperature swings add thermal expansion and contraction, which also works against the fastener. Moisture can cause rust, and rust changes the friction between the threads, sometimes making a bolt more likely to back off.
That does not mean every street bench will fall apart. Higher-quality benches use hardware made for outdoor conditions, such as galvanized or stainless steel bolts, nylon-insert lock nuts, serrated flange nuts, lock washers, or thread-locking compound. Tamper-resistant or smooth rounded bolt heads are also common in public settings to discourage vandalism. Many good installations combine several of these methods and include periodic checks.
If you are looking at a specific bench, check the hardware. Look for washers, lock nuts, and stainless or coated bolts. Firmly shake the armrest or backrest. A little flex in wood or recycled plastic slats is normal, but a clicking or shifting metal-to-metal joint usually means a bolt is already loose.
The good news is that this is fixable. A quick maintenance pass with a wrench, replacement of worn hardware, and a drop of blue thread-locker can make the bench solid again. If you manage public seating, inspect it once or twice a year, especially after winter. If you are buying a bench, ask about the fastener type and look for stainless or coated hardware.
So the short answer is yes: street benches are typically assembled with bolts, those bolts might loosen over time, but the right hardware and a simple maintenance routine can keep them safe and steady.