Stress relieve

[WindyParticipant @windy30762]

[WindyParticipant @windy30762]

I have made a batch of torsion springs for my steamer and according to my spring making literature have now to stress relieve them at 260C for 1 hour.

Apart from putting them in a domestic oven are there any solutions etc. that they could be put in to maintain an accurate temperature at home?

Paul

[jason udallParticipant @jasonudall57142]

Oven’s good but temp. Regulation might be poor. .and thermometer rather than the ovens “knob ” markings..for tempering I have used temperature crayons in the past.. but all that said oven would still be better for stability than “blowtorch” and bricks. .good luck springs are challenging.

[jason udallParticipant @jasonudall57142]

Oven’s good but temp. Regulation might be poor. .and thermometer rather than the ovens “knob ” markings..for tempering I have used temperature crayons in the past.. but all that said oven would still be better for stability than “blowtorch” and bricks. .good luck springs are challenging.

[Sub MandrelParticipant @submandrel]

Hi Paul,

See the thread on salt baths, or if you want a safer life a deep fat fryer on 'high' should do the job.

Be warned though, for some reason my little bits of steel are seen as harmful to human health even if they are lying on top of or inside steel cockware…

Neil

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Stub Mandrel on 20/06/2013 18:53:53:

Hi Paul,

See the thread on salt baths, or if you want a safer life a deep fat fryer on 'high' should do the job.

Be warned though, for some reason my little bits of steel are seen as harmful to human health even if they are lying on top of or inside steel cockware…

Neil

Is that your latest project Neil?

Russell

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hello Paul ,

They must be enormous springs – the time for stress relief varies with the size of component and the rule of thumb is one hour for every inch of section .

Seriously – if your springs are the usual model sizes then a few minutes would be more appropriate .

Stress relief as such may not actually make any difference – it depends on how the spring was made in the first place and what steel was used . In most cases rapid hardening and then rapid tempering to blue is the best option and any further heating will cause degredation .

Remember that when quenching that its the temperature of the work at the instant that it hits quenching medium that counts . A lightweight component can lose all its heat almost instantly when taken away from heat source .

Best way to heat all small components for any heat treatment is to clamp them to a more substantial piece of similar material and heat and quench the lot together .

If normal steel material then colour of the more substantial piece will tell you temperature quite accurately .

Be aware of the problem of distortion when heating – a poorly made spring can change shape altogether when heated .

Regards ,

Michael Williams .

[Sub MandrelParticipant @submandrel]

I was inspired by one of Blackadder's codpieces…

Neil

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Stub Mandrel on 20/06/2013 19:35:12:

I was inspired by one of Blackadder's codpieces…

Neil

[WindyParticipant @windy30762]

Here is part of the article on spring making **LINK**

When I first designed and stress relieved the springs that overcome a problem that I had with coil springs I used cooking oil but the risk from fire was great and wondered if there was a less inflammable oil for the temperatures required

[jason udallParticipant @jasonudall57142]

Re other oils…peanut/groundnut oil is reckoned to smoke less at higher temps. thus its use in stir fry. .just hope no nut allergy sufferers in household. ..

[Mark CParticipant @markc]

Jason,Neil,

A safer medium for tempering spring steel, if you must use industrial practise, would probably be lead (as long as you take the appropriate care and precautions). You could then use the molten lead to make sea fishing weights and have a few hours fishing in the fresh air. You could argue this was therapeutic on account of breathing the poisonous lead fumes (which is not the case as long as the temperature remains below 450 deg C or there about).

Mark

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