Paper Clip

invention · physics · office tool · everyday genius

Bent wire genius. A paper clip is just steel wire bent into loops, but those loops use something called torsion to grip your papers. When you slide sheets between the two metal tongues, they push apart and twist the wire, creating a squeezing force that holds everything together.

The Gem design rules. Most paper clips today are based on the Gem type, invented in the 1890s or earlier. It has one and a half loops, which is the perfect shape for gripping papers without damaging them.

Friction does the work. Paper clips don't use glue or magnets, they rely on friction, which is the grippy force between two surfaces rubbing together. The wire presses against the paper and friction holds them in place.

Portable paper bundle. Before paper clips, people used string, pins, or wax to keep papers together. Paper clips made it easy to bundle documents for moving around, which helped people stay organized at work and school.