Ball Bearing

machines · engineering · invention

Balls do the work. Ball bearings use round metal balls held between two rings to let things spin freely. The balls roll around smoothly instead of letting the metal rings rub against each other, which would create friction and heat.

Found everywhere. You'll find ball bearings in skateboards, roller skates, car wheels, bicycles, and even ceiling fans. Anytime something needs to spin smoothly without wearing out quickly, there's probably a ball bearing doing the job.

Keeps parts separated. The main job of a ball bearing is to keep two metal rings, called races, from touching each other. This separation means less friction, which makes machines run cooler, faster, and last much longer.

Ancient but modern. People have used the spinning ball idea for thousands of years, but the modern ball bearing we know today was invented in the 1800s. This simple invention changed how machines were built forever.

Comes in many sizes. Ball bearings can be tiny, like the ones in a computer mouse, or huge, like those in a giant ship's engine. Engineers design them with different sizes depending on what job they need to do.