In normal operation, do springs lose resistance over time?

[totse]

Thanks.

[Solomon]

In short, not really. I don't get the question though; I understand what you're asking but I have no idea why. Are you having an issue with something? Sometimes we need to put a question into context before we can answer it properly.

[Eyes_Only]

I thought that they could? That's supposedly why Master Lock decided to use stainless steel springs just for the one special bump stop top pin they put in their "bump resistant" padlocks.

[Slick Pick]

Master Lock used the stainless steel springs because conventional springs become weak after a number of bumping attempts.

http://www.bumpstopsecurity.com/locksmi ... _Jan10.pdf

[raimundo]

springs are typically made of specially purposed alloys, vanadium steel and such, but all metal work hardens, a good spring is subject to the second law of thermodynamics, organized systems tend toward chaos. A good spring will eventually break, and a bad one will weaken.

[Poff]

All springs fatigue to some extent over time. If you pull the top springs out of an older, used, lock core, they are usually visibly shorter then the new ones. The higher end locks probably use better springs so they are probably not visibly fatigued but still fatigued. This is why a cars suspension sags over time, same principal.

[totse]

Thanks for the good answers, everyone.