The greatest achievement of mankind, which caused the rapid growth of production capacity, was the production and use of iron. Iron finally replaced the stone tools, which neither copper nor bronze could do.

Before the invention of the iron rim, the undercarriage of the wheel, which came in contact with the road, was leather-covered and nailed with a wooden hoop. The rims of the wooden wheels were also made of separate curved pads and bent from a whole bar of a thin knit trunk. To reduce the weight of the wheel, they started to make cutouts and reinforce it with transverse scrapings for stiffness.

After people mastered metal and learned to smelt various metal products, a wheel with a metal rim appeared. This wheel was protected from stone bumps and rough roads, and had much higher wearing out resistance.

The first iron rims appeared on Celtic carts about 1000 BC. This invention made chariots, especially combat ones, easier and faster, and people began to explore new territories more successfully.