Any ideas from the engineering community - "How do you make a spring - 'spring' ???"

[gravity sucks]

I have a pair of minature reading glasses (don't mock - it will happen to you eventually) and they come in a tube with a "flip-top" lid.

Sods law - hinge pin drops out, spring goes "ping" - gone for good.



Beacause I'm a tight git I've made a new spring out of a biro spring but in doing so it's lost a bit of "body" and I was wondering if heating it up and cooling it quickly would help it...

Any ideas from the engineering community ???

ATB Toby

[Chris321]

If you heat it up and cool it quickly, it will become very brittle - not what you want from a spring (called quenching). There are 2 other heat treatments you can look at, one is called annealing, and the other is tempering. Wikipedia them for more info

To be honest, the best way would be to get a new bit of metal, or even more outrageous.....a new glasses case

[Smokeless Coal]

Spring steel can be annealed by heating it cherry red and cooling it very very slowly. Like over a 24 hout period. I do it to car leaf springs by building a bonfire and covering with ash and sand and leave it till next day. To make it springy again you heat it cherry red and quickly cool it, dunking in oil bath normally. The trouble is this makes it brittle it can shatter like glass sometimes. What needs doing to it to prevent this is tempering. It needs heating to 800 degrees and keeping there for say one and a half hours then cooling fairly slowly say an hour.

Thats just a basic description it can vary depending on the quality and thickness of the steel.

[Dave S]

For omething the size of a viro spring id try just "recalibrating" it by stretching it a bit past the length you want

Dave

[gravity sucks]

Thanx guys...

[Scooby]

The chances are the biro spring won't have a high enough Carbon content to harden properly.

If you heat it until bright Orange/Red & drop it into some water this will quench the spring but it will be very brittle & is likely to break when compressed. You now need to temper the spring which will slightly soften it but make it much tougher so it won't break, this could be done in the oven but you can lightly play a lighter flame over the spring a few times without it turning red, let the spring cool in air & it shouldn't break. If you want to do it in the oven, stick it to it's max & leave the spring in for 30mins - 1hr before removing & air cooling.