A brick has bumps on top, called studs. The studs fit tight between the tubes inside another brick.

Toy bricks are hard plastic. It starts as tiny grains.

Giant tanks called silos hold the grains. Tubes in the factory send the grains to the machines.

Color is added at the machine. One plastic can make bricks of many colors.

A machine melts the plastic. Then it goes into one side of a mold.

The hot plastic spreads in small paths. It fills a space shaped like a brick.

Cold water flows through the mold. It cools the plastic fast. Then the mold opens. The bricks fall on a belt.

Plastic left over from the mold is ground up. It is used again almost right away.

Some bricks have faces or patterns. Machines print or stamp them on.

Machines weigh each box and bag. They flag any too light or too heavy. Then a person can check.

As of November 2026, LEGO is the best-known brick maker. It is based in Billund, Denmark.

Old bricks can fit new bricks. The brick has stayed the same since 1958.