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Spring steel

General discussion on any topic which doesn't have a natural home on any of the other boards.
StephenB
Posts: 152
Joined: 26 Dec 2018, 08:45
Location: Hungary

Re: Spring steel

Post by StephenB »

Well, the next problem is how do you drill it??

I've tried a normal drill bit at varying speeds and a diamond bit in the Dremel, neither of them have any effect whatsoever.

Failing me not being able to drill the steel are there any suggestions for a different material to produce the tailskid from?

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Barry_Cole
Posts: 1389
Joined: 10 Mar 2015, 09:30
Location: Hampshire UK

Re: Spring steel

Post by Barry_Cole »

If you use this:-

https://www.ajreeves.com/search/for/spring+steel/

You can drill it, and then temper it after drilling and bending.

BC

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Peter Balcombe
Posts: 1098
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Spring steel

Post by Peter Balcombe »

Barry,
If Stephen finds it difficult to get hold of suitable annealed steel in Hungary, I suppose he could try annealing what he has (by heating to red heat), drilling & bending as required) then tempering the result?
Worth a try?

Edit: I now see that modern hacksaw blades are usually made as a strip of harder tool steel (teeth) electron beam welded to a backing strip of softer material for the main blade in order to give hard wearing teeth on a less brittle blade.
Thus not sure what the carbon content is of the main part of the blade (which is presumably what Stephen has cut away for his skid).

StephenB
Posts: 152
Joined: 26 Dec 2018, 08:45
Location: Hungary

Re: Spring steel

Post by StephenB »

Thanks for the helpful replies Barry and Peter, I had looked at that source of steel previously but baulked at the shipping cost to Hungary. I cut the blank from a large cross cut saw not a hacksaw blade if that makes any difference Peter. To "soften" it do I heat it to red hot then let it cool naturally or dip it in water, which I understand is the process of annealing it??

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Peter Balcombe
Posts: 1098
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Spring steel

Post by Peter Balcombe »

Stephen,
If it was a normal wood saw blade then I should think you have suitable carbon steel as another website I looked at said that one of the popular uses of spring steel as used for leaf springs etc. was saws.

Yes, I think you will find that heating to a red heat (theoretically held at temperature for a while for thicker sections) & then allowed to cool slowly should achieve an annealed material. (Don’t quench). (Industrial annealing uses ovens which are programmed to follow temperature/time profiles, holding at temperature for an hour or more, then slowly reducing temperature over several hours - Google Annealing process.)

Tempering needs steady heating to get the whole workpiece to a chosen colour (colour is a good indicator of temperature) to achieve the desired hardness, quickly quenching in water when the colour/temperature has been reached to ‘fix’ the hardness state.
I think I went for a light blue colour temperature, but cannot remember now (May have been straw ;) )

You can always rough check hardness by drawing a file across an edge before a bend test by flexing between fingers.
Too soft & it will just bend whilst too hard will make it brittle/break.
Look up a tempering colour chart on the web for guidance.
If too soft then you can try a higher colour.
If you overdo the temperature then you can re-anneal & start again.

I’m sure Barry will chip in if I haven’t got this right :)

StephenB
Posts: 152
Joined: 26 Dec 2018, 08:45
Location: Hungary

Re: Spring steel

Post by StephenB »

Thank you Peter, very helpful.

Keith
Posts: 75
Joined: 07 Jan 2019, 18:18
Location: Lincolnshire

Re: Spring steel

Post by Keith »

Try a cobalt drill used them on stainless steel.

Keith

John Vella
Posts: 240
Joined: 20 Mar 2017, 22:09
Location: UK

Re: Spring steel

Post by John Vella »

I also have had success with a cobalt drill turning at low speed on spring steel for holes on my MU13 tail skid. Regards John.

Keith
Posts: 75
Joined: 07 Jan 2019, 18:18
Location: Lincolnshire

Re: Spring steel

Post by Keith »

If you let me know what size you want I'll have a look and see if I have the size.

Keith

paulj
Posts: 46
Joined: 23 Dec 2018, 17:51
Location: North Wales

Re: Spring steel

Post by paulj »

To be a little pedantic regarding hardening and tempering. Normally this is a two stage process - heat and soak the components at a temperature which ensures crystalline phase change in the steel to austenite. Quench in water or oil (the latter is gentler due to the temperature transfer rate). The parts are now very hard, but also brittle. Next comes tempering - heat the parts to a lower temperature (< 200C) to start the phase transformation from the martensite structure created when the parts were quenched. Tempering also requires some time. I would recommend playing around with the process to get the correct amount of hardness.

Once all your fabrication is done, with the thin section of the material being used you could quench it in oil, then it may be OK to use without further processing. I guess you want it stiff enough not to bend when it contacts the ground. Brittleness may not be such an issue in this case. Of course you won't be able to do any more work on it in the hardened state (as you have found).

Wikipedia has more information: https://en.wikipedia.org/wiki/Tempering ... ched-steel

(I did a materials science degree in 1983-1987!! It's been a long time...)

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