Taking a blowtorch to stainless for springs and pins

S

Snickersnee

Joined
May 2, 1999
Messages
1,206
For the project I'm working on, I'm going to have to do some bending on some heavy-gauge 440C(1/8 for leafspring), and I'm considering using a propane or mapp torch to soften it up to make it easier to work.

I know that you can't weld stainless with a flame(discounting specialized flux) as it causes it to "carburize" for lack of a better term. I know some guys are forging stainless, and I was wondering if you can heat to red or maybe orange with a flame safely, or if you have to use an electric furnace or somesuch.

Also, I will be using very beefy pins, 1/4 inch, and I'm think about doing this to make them easier to peen over. Any thoughts?
 
Go ahead and heat the 440C to bend it but not to peen it.

Get the material to a bright orange colour and bend quickly. Heat an area larger than the bend or the bend could crack at the edge of the heated zone.

I have done this several times on lock back locking bar/spring components with no problems as long as I spread the heat and bent the spring while it was hot. I used heat because cold bending of the spring invariabley caused cracks.

Any embrittlement caused by my torch was removed during the subsequent heat treating stage.

By all means anneal the pins so long as they are not heat hardenable, you could end up with pins that are too hard to peen.

------------------
george
www.tichbourneknives.com
sales@tichbourneknives.com

 
Please stop , do not use 440-C for a spring it won't last. sure it might work for a little while but it will relax as well as eventualy break. I've built a lot of autos and hands down the best material i've ever used is believe it or not 304 work hardened material I bought from Rendon Griffon. he gets a spring company to take round spring wire and flatten it to your specs.
You can bend it weld it and it just keeps kicking. No corrosion ,no problems and it will make your autos kick like a mule.
Rendon's Phone # is in the Knife annual under Knifemakers
He also builds some pretty cool classic patterned autos.
Aloha!!! Ken Onion
 
It says there are two replies here, but I'm only seeing one, so...

How would you reccomend peening 1/4 thick hardenable steel pins?
 
Ken, thanks for the head's up.

About this 304, I've got to do some radical bending on it to get it into the shape I need, and because of the necessary thickness I can't think of a way to shape it without heating it up.

Anyway, won't that destroy the work hardening by annealing?

Gee, and I though this project was gonna be easy...
smile.gif


(p.s. yours was the post that wasn't showing up)
 
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