Tension springs are similar to compression springs in the coils, but require special edges so strength can be applied. These edges, also known as hooks or loops, may vary in shape depending on the application.
They need to be stretched in order to fulfill their function, increasing the space between the coils and thus the size of the spring. By ceasing this, the spring goes back to its original length.
d - Material Diameter Lh - Eyelet Length Da - External Diameter Di - Internal Diameter Lk - Spring Body P0 - Spring preload lf - Number of active coils m - Eyelet Opening L0 - Free Length L1 - Height to P1 load P1 - Load needed for L1 L2 - Height to P2 load P2 - Load needed for L2