Tension spring (tension spring) is a spiral spring which bears axial tension. It is generally made of circular cross-section material. In the case of no load, the tension spring between the coils is generally tight and there is no gap.
It is widely used in machines and instruments to control the movement of machine parts, store energy and measure the force by using the elastic force (tension) after stretching. There are side hook tension spring, long hook tension spring, British hook tension spring, German hook tension spring, semicircular hook tension spring, duck beak hook tension spring and so on.
Its materials are stainless steel, piano steel, high carbon steel, phosphorus copper, beryllium copper, oil tempered alloy spring steel, etc.