# Lock Spring



## mrpercysnodgrass (2 Feb 2013)

One thing I have always struggled with is making small springs like the one in the photos below. I usually nick one from another lock with the result I now have a drawer full of locks with no springs.
Does anybody have experience with making springs like this? And if so can you give me a few pointers. I am quite good at braizing and making all sorts of brass and steel components but my attempts at springs has at best been poor and not given me a working spring.


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## Spindle (2 Feb 2013)

Hi

Not wishing to insult your intelligence by stating the obvious - but are you starting with the correct material? (spring steel / piano wire). It can be obtained it in small quantities, example below, (the catalogue needs to be downloaded).

http://www.m-machine-metals.co.uk/mm/website/index.html

Regards Mick


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## mrpercysnodgrass (2 Feb 2013)

Thanks Mick, that is the sort of thing I am after, What is the "swg" in the catalogue? I tend to use scrap that is around but after cutting to shape the spring goes out of the metal, I understand that to get the spring back it has to be heated and then cooled in the correct way, I think that is where I am going wrong.
I suppose what I am after is a step by step guide from somebody that knows what they are doing, ie, buy this metal from there, cut to size, heat to this colour cool like this.
P.S. there is very little intelligence, so no insult taken!


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## Spindle (2 Feb 2013)

Hi

There's a lot of useful info on this site if you have an explore:

http://springsteelstrip.co.uk/2008/09/0 ... tempering/

SWG - Standard Wire Gauge - see:

http://en.wikipedia.org/wiki/Standard_wire_gauge

Regards Mick


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## Hutzul (2 Feb 2013)

I've dabbled a bit with these springs also. I tend to keep a few bits of spring steel for broken locks etc. A cheap source of spring steel (ss), used to be the blue steel strapping used for palletised goods, though I aint seen any for quite a while. Some coil springs can be had from old mechanical clocks and pillar drills.

The hardest part will be getting the old spring out of the pawl / lever without damage as brass fractures easily, I would be tempted to make a pattern of the spring shape before removal, then heat the part where spring is secured and try to wiggle it free.

This worked for me last year, when my mothers wrought iron door handle return spring broke. I couldn't find a replacement handle in keeping with existing door furniture so repaired the broken spring. 
The ss I had was too wide, so I clamped a piece with the surplus width above my vice jaws and ground it down with angle grinder. The vice jaws kept the ss cool enough to keep its 'spring'.

Hardening & tempering is QED, as mentioned above.

Hope this helps and good luck.


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## Mister Griffiths (2 Feb 2013)

A good source of spring steel is the mainspring from an old clock, as long as the clock is not worth repairing! Sometimes you can buy a job lot of them on places like eBay for peanuts.

It goes without saying, mind, to be phenomenally careful if removing the mainspring from a casing. Those will take your eye out in a heartbeat...


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## CHJ (2 Feb 2013)

Cherry red and quench in oil.
Polish and heat evenly to blue, the most difficult part due to small volume and quench in oil.







If you can work piano wire without heating it up to the tempering temperature (cold work) it should work as is.


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## Mister Griffiths (2 Feb 2013)

You might find it easier to get it heated to blue evenly if you do so by placing it on a tray of sand and heating that. It diffuses the heat nicely, and allows a bit more control over small items


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## mrpercysnodgrass (3 Feb 2013)

Thank you all, there is some useful information for me there, I have plenty of old sprung steel packing straps and I will ask our clock man if he has any springs he can give me, I think where I have been going wrong is in the final tempering/blueing, so I will definitely have a try with the tray of sand.


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## Setch (3 Feb 2013)

I realise this probably runs contrary to the spirit of the above posts, but you can also get the appropriate spring stock here, and avoid a lot of work trying to re-purpose other material:

http://www.springman.co.uk/epages/es138 ... Products/V


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