Useless fact
What are the bumps on top of a Lego brick called?
The small, round bumps on the top of a Lego brick are officially called studs.
The interlocking mechanism of Lego bricks relies on a system of projections and tubes. The small, cylindrical bumps on the top surface of each brick are officially called studs, a term established in the original 1958 patent by Danish inventor Godtfred Kirk Christiansen. These studs are designed to fit snugly inside the tubes on the underside of another brick, creating a temporary yet sturdy connection known as clutch power. The precision of these studs is remarkable, manufactured with a tolerance of just one-thousandth of a millimeter to ensure they are neither too tight to pull apart nor too loose to hold together. While casual builders often refer to them simply as bumps or dots, the LEGO Group, toy historians, and adult fans of Lego consistently use the term studs to describe this fundamental component of the building system.
Why this is true — The original 1958 patent for the Lego brick (US3005282A) explicitly describes the protrusions on the upper face as 'studs', which remains the official industry term.
Sources
- Toy building brick United States Patent and Trademark Office
- LEGO The Strong National Museum of Play