The material commonly used for the adjustment spring in headphones is manganese steel. Manganese steel is an alloy steel that contains a high proportion of manganese element. It has good elasticity and toughness, suitable for manufacturing parts that require elasticity and withstand certain loads.

Manganese steel adjustment springs play a role in adjusting and adapting to different head sizes in headband headphones. This type of spring is usually located between the two side frames of the earphones. By adjusting the stretching or bending degree of the spring, the tension and tightness of the earphones can be changed to adapt to different head sizes and comfort needs.

Manganese steel adjustment springs have good corrosion resistance and durability, and can be used for a long time without losing elasticity. They usually have a certain degree of torsional elasticity and can be bent and restored to their original shape to meet different requirements.

Overall, manganese steel adjustment springs are a common component in headphones, used to adjust the tension and comfort of the headphones. Their material selection is manganese steel to ensure the elasticity and durability of the spring.