LOOKING for elastic materials

Only if you don't use it. Rubber under tension will lose tension, due to cold flow (also known as creep). Silicone elastomer will be more resistant to oxidation and crosslinking, but the mechanical properties of silicone are poor compared to rubber.

If possible, you should use a metal spring. What is the application?

Dear Mark,

thank you for your answer.

The spplikation is hinges in a box and there will be low tension until the lid is opened 2 times a day and then low tension again.

so i think i go for a metal spring.

best regard Soren M

A spring operating within its limits is one of the most reliable mechanical devices. This may be hard to believe, because almost everybody has seen a broken spring. But it is important to include a limit stop to prevent the spring from being overstressed. This can usually be included at little or no cost, for example by adding a spur to stop sliding or rotating parts.

If your application allows it, you might consider providing the restoring force in the form of a weight on a small chain.

Thank you Mark,

the spring shal be used in a box door in light trassperent plastic mesuring

i think that i go for the spring that stay within the limits so it doesent brake.

best regards Søren M

"Mark Thors>

It might be easier to use a compression spring, which I've seen but I don't know if they're commonly available. They have a hook-like thing that goes through one end and grabs the opposite end. And another one going the other way. So when you pull on the hooks, the spring compresses until its coils are touching, and then it can compress no more.

Hello Gregory,

i dont know that kind of springs, is there at picture i can see some time please?

Best regards Søren M

"Gregory L. Hansen" skrev i en meddelelse news:csc2a0$68o$ snipped-for-privacy@rainier.uits.indiana.edu...

I just have vague memories of something I'd seen before. But if you browse the hardware store and they have it, I'm sure you'd recognize it. If they don't have it, maybe it doesn't matter.