Small metal spring.
Toys for kids, drastic life-saving devices, and dramatic life-ending devices are all made possible with the seemingly innocent mechanical spring. Springs are known for their elastic nature; they kneel with stress, but return to their original shape once that stress is removed. When a spring is tightened, it stores the energy given to it, which is released when the spring is allowed to loosen. Springs are also great for absorbing energy, making them useful for shock absorbers; this is their primary use in a firearm's bolt assembly. Most springs are made from alloys based on iron, with some carbon and other elements.
Springs can be found just about anywhere, from mechanical wind-up clocks and toys to shock absorbing springs underneath cars, to the springs inside the mattress of a bed to the springs inside trampolines and pogo sticks, and to the little spring in a retractable pen that always breaks after mindlessly playing with the button for hours on end.
- ↑ "How do springs work? | How do springs store energy?". explainthatstuff.com. 9 September 2009. Retrieved on 29 July 2015.