I found these small metal balls on the ground  They’re very hard, impossible to crush or melt  I had never seen anything like this before  Later I looked it up online and honestly, I was shocked.

I’ll tell you what these balls are for. Continued in the first comment 

At an abandoned truck parking lot, covered with fine gravel and rusty nuts, we found a strange pile of tiny metal balls.

At first glance, they looked like small ball bearings, but they were too perfectly round and smooth. Each sphere shone in the sun and seemed completely resistant to corrosion despite being outdoors.

We tried to crush them — no luck. Tried to melt them with a lighter — useless. The material was obviously very tough. Their shape and uniform size made us wonder where they came from.

I asked a friend who has worked in trucking for many years. He immediately recognized the balls and explained:

“These are balancing balls,” he said. “They’re filled inside tires to balance the wheel while it’s rolling.”

Instead of putting weights on a balancing machine, drivers simply pour these balls inside the tire. When the tire spins, the balls find the right spot themselves to balance the rotation. Cheaper and faster — especially for heavy trucks.

Later I did some research. It turns out these balls really are used in truck and off-road tires.

They’re made of hardened steel to withstand high temperatures and pressure inside the tire without breaking or losing shape.

Sometimes they have an anti-corrosion coating or are made from composite materials to reduce weight, but most often they’re steel — the strongest and most durable.

When the truck accelerates, these balancing balls spread evenly inside the tire and automatically compensate for any imbalance — because a wheel can lose balance if the tread wears or the load changes.

That way, the tire “adjusts” to any driving conditions.