The material spring steel and music wire are the largest.

1. Spring steel has good elasticity and fatigue resistance, which allows it to maintain a stable shape when subjected to repeated impacts or pressure changes. Typically contains higher carbon content and alloying elements such as silicon to improve its mechanical properties and temper stability.

2. Music wire is a material specially used to make musical instrument strings or other acoustic equipment, such as piano strings and guitar strings.

This type of steel is characterized by excellent elastic modulus, low internal damping and good response to sound propagation