system
Given the following post, respond as if you're commenting on Reddit:
human
How do springs continue to apply pressure over years?

I repair classic record players, and I've always been amazed that the internal springs can still do their job, even on a 40 year old player. It always seems like they should be much more stretched out than they are, and while I have to replace or rejuvenate some, the majority still work perfectly. How is this possible?
gpt
Materials have what is called an elastic limit.  

It is essentially the amount of deformation that a material under force can undergo such that when the force is removed, the material will return to original shape/position/size.  

As long as you don’t exceed this limit, it will continue to bounce back.  If you go beyond this you will cause plastic deformation, which happens when you stretch out a spring too far and it doesn’t go back.