Hardening, Tempering and Heat Treatment

[Bodgeit and scarper ltd]

I have been trying to find information on the Internet without any luck on Hardening, Tempering and Heat Treatment, can anyone point me in the right direction. I need to make some very small leaf springs

 

[Stivino]

http://www.technologystudent.com/equip1/heat1.htm

That kind of thing?

 

[Trazor]

To successfully harden and temper small leaf springs, I would proceed as follows:-

Ideally you will need a hole in your leaf springs, to enable you to suspend them with some fine wire.
To support them as shown in the link will result in the ends being harder to get the same colour as the centre.

Suspend your leaf spring above an oil bath, not water, water gives too severe a quench.
Heat the spring, using a small nozzle on your Oxy-Acetylene set, until Cherry Red. Be careful, its easy to destroy the edges of thin spring steel with to fierce a flame.
Immediately douse the spring in the oil bath, and leave until cold.
Now clean your spring with wire wool, or fine emery paper until it is bright.
Next heat the spring, until you get a uniform straw colour.
Now bury the spring in DRY sand until cold.

Clean again if required.

 

[Bodgeit and scarper ltd]

Thanks for advice and link to site

 

[marshman]

Trazor,
why straw colour then the slow cool ?
as opposed blue then oil quench.

 

[Symptoms]

Bod - I've made quite a few small springs over the years when restoring firearms (a hobby of mine). If you want specific information post again but you could get a copy of Tubal Cain's book on the subject - Spring Design & Manufacture (I've got an old copy) but it is available on Amazon, link below:

http://www.amazon.co.uk/Spring-Design-Manufacture-Workshop-Practice/dp/0852429258

 

[Bodgeit and scarper ltd]

Thanks Symptoms I think I can make them now, I have found some thin spring steel for the two smallest springs, the third spring needs to be thicker at the ends I am thinking a bit off the end of a car leaf spring may do this