Grades K–2 · Everyday Life
How do the two halves of a snap stay together?
A snap fastener has two matching halves. One has a small raised stud. The other has a socket with a springy part that can move slightly.
In the diagramA springy socket catches behind the studBeforeJoinedspring retains head
As the stud enters, it pushes the springy part aside. After the wider part passes, the spring moves back toward its usual shape. It catches behind the stud and helps hold the halves together.
Pulling the halves apart moves the spring aside again so the stud can leave. A small bend lets the same closure open and close many times. No glue has to be added each time.
About this explanation
Starting knowledge: Recognize two matching fastener halves on clothing.
Sources
- Prym — Snap fasteners, brass