Ring connection
（重定向自Spiral connection）
The ring connection sometimes called comb-bound or spiral connection is a popular book or kind of sheet connection, which binds pages using spiral wires. It is normally made of metal wire, which from a double spiral is formed, which is punched into paper sheets and it binds them. Sometimes it is made of plastic. This gives smaller costs, but the same stable as ring connections made of metal wires. The only problem with ring connection is that pages bound using it are sometimes wasted when are they torn out.