An extension spring is a component that creates a resistance to a pulling force. Extension springs work by trying to pull two objects back together. The attached spring is pulled in opposite directions and the force and the stored energy to pull the two objects back together.
Extension/Tension springs can be developed for flexibility in terms of length and hooks or loops for fixation. Extension springs have a wide variety of applications including return springs for doors, in washing/drying appliances, agricultural equipment etc.
Metrol manufacture tension springs using two main materials, unalloyed spring steel and stainless spring steel.