I have a question for you. What kind of force is the initial tension of the springs?
Extension springs’ coils are usually in a closed-contact state. Torsional stress is generated by the coils’ bonding even when there is no load. This is called initial stress. The spring does not change in the load direction unless a certain amount of load is applied. The load that makes the spring begin to change in the load direction is called “initial tension”.
