Editing Coil spring (section)

== Manufacture ==

Metal coil springs are made by winding a wire around a shaped former{{snd}} a cylinder is used to form cylindrical coil springs.
[[File:Bogenfedern und Bogenfedersysteme.jpg|thumb|Illustration of various [[Arc spring|arc springs]] and arc spring systems (systems consisting of inner and outer arc springs).]]
Coil springs for vehicles are typically made of [[hardened steel]]. A machine called an auto-coiler takes spring wire that has been heated so it can easily be shaped. It is then fed onto a lathe that has a metal rod with the desired coil spring size. The machine takes the wire and guides it onto the spinning rod as well as pushing it across the rod to form multiple coils. The spring is then ejected from the machine and an operator will put it in oil to cool off. The spring is then [[Tempering (metallurgy)|tempered]] to lose the brittleness from being cooled. The coil size and strength can be controlled by the lathe rod size and material used. Different alloys are used to get certain characteristics out of the spring, such as stiffness, dampening and strength <ref>{{cite web|title=How Springs Are Made|url=https://www.thomasnet.com/articles/machinery-tools-supplies/how-are-springs-made|website=Thomas|access-date=19 April 2018}}</ref>