Leonardo da Vinci is credited with sketching an early ball-bearing design.
Around 1498, Leonardo drew mechanisms using balls placed between moving surfaces. The purpose was to reduce friction while allowing one component to rotate relative to another. His drawings included ideas for keeping the balls separated, an important problem in bearing design.
The concept was not yet the standardized, enclosed bearing used in modern machines. Renaissance engineers understood friction practically, but manufacturing precise, durable components remained difficult. Leonardo’s sketches therefore show an important mechanical insight rather than a finished industrial product.
Ball bearings are now used in bicycles, electric motors, tools and many other machines. They differ from roller bearings, which use cylindrical or tapered rollers instead of spherical balls. Leonardo’s drawings are often cited in histories of engineering because they show a clear early attempt to control friction through rolling contact.