Patch box catch spring tempering

[Chowmi]

I have a patch box spring catch that came with the patch box.  it arrived "as cast", so I assume I need to harden, then temper it (after I finish filing it, obviously!).

I was thinking to harden, quench in oil, then temper to color.  But what color?  I don't have a heat treat oven with precise temperatures.  Or is there a better method than tempering to color?  Lead bath?  I don't know much about springs.

Here is the spring:




It will poke up through a hole and serve as both catch and spring in this box:





Cheers,
Norm

[rich pierce]

Go to bright blue then a little further. One way is to lay on sheet steel or brass and heat the sheet from below with a torch. Sliding patchbox springs and catch springs like this one  flex very little. Low risk and some use mild steel.

[smylee grouch]

I went to an orange color ,quench in HYD.oil and then lead bath. I don,t think the spring got that hard in the quench and after the lead bath I could still stone it with little trouble but it turned out well and worked well now for about 20 years.

[David Rase]

Once the spring is filed and shaped, heat it up with either mapp or oxy/acetylene to red.  Quench in a light oil such as canola.  Once hard, polish the spring.  Next, clamp a piece of steel bar stock, maybe an inch or inch and a half wide and 1/8" thick into your vise.  Lay the spring on top of the steel bar and heat with a torch, I use propane, from the underside watching for the spring to turn blue.  Once blue, remove the flame and slide the spring down the steel bar to a cooler section of steel so the spring does not continue to absorb heat.  Once cooled, you should be good to go.
David

[Jim Kibler]

No need to harden and temper.  This spring will have such little travel, it won't be necessary.  If it's "as cast" it will have a bit of hardness to it anyway.  We don't harden and temper our box lid springs for our Colonial Rifle Kit.

Jim

[Chowmi]

Guys,
Thanks for all the replies. That all sounds good. I had guessed blue was about right.

I think I will try that.

Jim,
I hear what you are saying about your wooden box catches, I even used yours on one of your kits! 
My worry is that this catch is so stiff it won’t flex enough to release the box lid without stressing the screw/wood where it will be attached.
I suppose I could just file it thinner!

I’ll try the tempering first, then thin it if needed.

Thanks! 

Norm.

[Jim Kibler]

Tempering won't help with the thickness / stiffness issue.  You'll have to decrease the thickness regardless of how it's heat treated.  The only thing heat treatment will do is allow the spring to be bent further and still come back to the same shape (relative to a non hardened and tempered version).

Jim

[Chowmi]

Tempering won't help with the thickness / stiffness issue.  You'll have to decrease the thickness regardless of how it's heat treated.  The only thing heat treatment will do is allow the spring to be bent further and still come back to the same shape (relative to a non hardened and tempered version).

Jim

Jim,
Thank you, I hadn’t really thought of it that way. Also occurred to me to just install it first and see how it works.

Cheers,
Norm

[jerrywh]

In my opinion. Everybody who chimed in is correct. It will work either way. You don't need to temper but if it makes you feel better do it. Sooner or latter you need to learn to temper springs anyway.

[Chowmi]

Thanks again all, for the replies.  I installed the spring catch yesterday, after filing it.

No surprises here, Jim Kibler was right.  It works just fine as cast.  It's a little bit stiff, so I will file it skinnier. 

That is not to say that the advice on spring tempering was in vain, I shall file that away for future use.  Probably quite soon, as I need to make the lid spring.  If only I had some spring steel....  I'll have to scrounge around, one of my favorite things to do!

Cheers,
Norm

[Adrie luke]

Hello Norm,

Is everything oke?
For the lidspring you can use an iron saw.
You have to heat it ablaze, reddened.
Cool it natural.  Than it is soft and you can make what you want.
Are you ready, heat it again, cool in sunflower oil and your work is hard and fragile.
You have to temper it, I do it on a griddle, 3 minutes.
After this you have a nice lidspring.

[Chowmi]

Hello Norm,

Is everything oke?
For the lidspring you can use an iron saw.
You have to heat it ablaze, reddened.
Cool it natural.  Than it is soft and you can make what you want.
Are you ready, heat it again, cool in sunflower oil and your work is hard and fragile.
You have to temper it, I do it on a griddle, 3 minutes.
After this you have a nice lidspring.

Adrie,
We are well, thank you.  Beautiful sunny day here, wish you could join us! 

Thank you for the spring idea, I tried the same thing yesterday, but I did not get the tempering right so it did not hold shape.

I just learned that the original gun did/does not have a lid opening spring, so I will leave mine without it. Saves me some work!  I will practice with saw blades anyway. It is a skill I need to learn.

Hope you are well,

Norm.

[tallpine]

A good easy to come by source for spring material is old single spring traps. I just made a patch box latch from one a few days ago.