A tension spring, also known as a tension spring or tension spring, is a type of spiral spring specifically designed to withstand axial tension.
They are usually made of circular cross-section materials (such as spring steel), and when not under load, the coils of the tension spring are tightly connected without any gaps between them. The main function of a tension spring is to utilize the rebound force (tension) after stretching, which can be used to control the movement of components, store energy, measure the magnitude of force, and so on. There are various forms of hooks for tension springs, including side hooks, long hooks, British hooks, German hooks, semi-circular hooks, duckbill hooks, etc. These "hooks" ensure the source of tension for tension springs. Most tension springs work under a certain degree of tension, even when there is no load, this initial tension determines the tightness of the tension spring coil when there is no load. The working principle of a tension spring is opposite to that of a compression spring. The compression spring acts in the opposite direction when compressed, while the tension spring acts in the opposite direction when extended or pulled apart, attempting to pull the two back together and absorb and store energy.