Author Topic: does a spring under constant tension age?  (Read 6234 times)

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Offline Circlotron

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Re: does a spring under constant tension age?
« Reply #25 on: October 24, 2023, 11:43:05 pm »
 

Offline joeqsmith

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Re: does a spring under constant tension age?
« Reply #26 on: October 25, 2023, 01:31:40 am »
Shown is my homemade spring rate checker.  I use this to measure both my clutch and valve spring rates.  Yes, they change.   Borrow a torque wrench from a mechanic some time and don't release it. 
 

https://akotorque.com/torque-wrench-maintenance/

Quote
The accuracy of the click wrench is dependent on the spring maintaining its designed elasticity. If the spring remains loaded under compression for extended periods it will start to conform to that shape, causing the spring to lose its elasticity and its accuracy by changing the amount of tension applied to the click block. This makes it very important to release the tension on the spring when not in use. This is done by adjusting the micrometer handle to its lowest setting during storage.

Offline CatalinaWOW

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Re: does a spring under constant tension age?
« Reply #27 on: October 25, 2023, 03:53:45 am »
Valve springs and torque wrench springs are not lightly loaded.  The closer you get elastic limit you get the more possibility of relaxation you get.  And valve springs are flexed across this range hundreds of times a minute, at elevated temperatures, often for many hours at a time.  Even though the OP has provided no details beyond "lightly loaded" I think he is looking at a different environment.
 

Online ebastler

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Re: does a spring under constant tension age?
« Reply #28 on: October 26, 2023, 05:15:59 pm »
"Hope springs eternal."

 :-+

Whether or not that was meant as a pun, I enjoyed it a lot! ;D
 

Offline MarkT

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Re: does a spring under constant tension age?
« Reply #29 on: November 13, 2023, 08:01:13 pm »
if there is a spring on a light tension, a small weak one, does it age? I don't mean in a mechanism. Just between two posts.

I heard like 100 years+

Hard to find info because its all car related shit that comes up
In light tension, at room temperature, no, there'll be no measurable creep in a spring-steel spring as its simply too cold.  Heat it, stress it strongly and creep will become measurable.  Piano wire has a spring steel core for instance.

Mild steel, very different microstructure, very different behaviour...
 

Online coppercone2Topic starter

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Re: does a spring under constant tension age?
« Reply #30 on: November 14, 2023, 05:14:45 am »
they should put a lightly tensioned spring in one of those long range time capsules.
 

Offline MarkT

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Re: does a spring under constant tension age?
« Reply #31 on: November 17, 2023, 08:47:36 pm »
Interestingly certain polymers achieve close to zero-creep these days, for instance dyneema brand UHMWPE is alleged to have a 250 year creep life at 20% of breaking-strength...
 


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