A torsion spring is a spring that functions by twisting or twisting. It is a flexible elastic object that stores mechanical energy when it is twisted.
When twisted, it exerts a force in the opposite direction, proportional to the amount of angle that twisted.
In some usage, it is combine with sort of rod to keep its shape and keep the endurance and performance.
I managed to simulate how the torsion spring was made and well designed. Using finite element analysis (FEA) method, we could model and tested out the prototype design. So during fabrication and mass production the product quality have kept.
Cross section of the torsion spring
Then you could also have examined inner section of the torsion spring. Because shear stress of the spring also very important to design wise and specifications.