Is a hollow circular metal fastening ring with a spring opening that uses a tiny spring to keep the arm of this clasp closed. It is one of those clasps found on bracelets and necklaces that you pull back the little lever, push the ring into it and let the little lever go. We all know them.

A spring ring is a round, tubular metal fastening ring with a spring-loaded gap.

A mechanism used to join two pieces of thread or cord when creating jewelry.

A spring ring (also known as a bolt ring) is a hollow circular metal fastening ring with a spring opening. A tiny spring keeps the arm of this clasp closed. It is used to attach two other rings or links of a necklace or bracelet. The spring ring was invented early in the 1900's. Jewelry made prior to 1900 or so will not have a spring ring clasp.