Yes—street benches absolutely can have hidden screws, and they do loosen over time more often than people expect. I’ve spent enough time around public seating and outdoor furniture to see the same pattern: the visible bolts usually stay okay, but the hidden fasteners under the seat slats or behind plastic end caps are the ones that start backing out.
The most common hidden spots are under the wooden or metal slats where screws are driven up from below, behind armrest mounting brackets, inside or behind plastic and rubber end caps that cover bolt heads, at the base flange or concrete anchor points where a cover plate hides the hardware, and where the backrest frame meets the seat frame, especially on curved designs.
They loosen for a few reasons. Outdoor temperature swings make metal expand and contract. Wood and plastic slats swell when wet and shrink when dry. People sit, shift, and sometimes rock the bench. Over time, vibration and load cycles work screws backward, especially if they were installed without thread locker or lock washers. Rust can also eat away at threads and make a screw feel tight when it’s actually losing clamping force.
If you’re checking a bench, don’t just wiggle the seat. Flip it over if you can, or run your hand under the edges. Look for gaps that weren’t there before, rust streaks around hidden fasteners, and any popping or creaking when someone sits. A screw that has loosened but not fallen out may leave a small dark ring or rust dust around the hole.
For maintenance, I’d recommend stainless steel screws for outdoor benches, a nylon-insert lock nut or thread-locking compound, and a regular check every few months in public spaces. Most hidden screws aren’t dangerous on day one, but if several loosen, the bench can become wobbly, splinter boards, or even collapse at a connection point. So yes, hidden screws are real, and they deserve a little attention.