Grades K–2 · Everyday Life
How does a paper clip hold pages without glue?
A paper clip is one piece of wire bent into loops. Some wire lies on one side of the pages, and some lies on the other. The pages push those parts a little apart.
In the diagramSpringy wire squeezes the pagesEnlarged side view · wire bend is exaggerated2 pages separate the wire slightlyWirePaper stackOpposing squeezeThe grip comes from the wire shape and rubbing contacts.
The wire is springy. It tries to return toward its earlier shape, so it presses on the pages. The squeezing helps the paper rub against the clip and against other pages instead of sliding away easily.
A clip holds only a small stack well. Bending the wire too far can leave it spread out, so it no longer squeezes as it did before. The useful part is not just the metal: it is the metal bent into a springy shape.
About this explanation
Starting knowledge: Recognize pages, wire and a gentle squeeze.
Sources
- William H. Redington · US patent disclosure — Paper-clip · US776549A
- MIT OpenCourseWare — Introduction to Biological Engineering Design: Class Notes, Week 10