A Forging Question

[DC]

I have a couple of "C" clamps I've had for years. I bent them when I was into cars and they don't line up quite right. They work, but can be awkward. They are good forged clamps. I'm wondering if a forging like that will lose strength if I heat them to straighten them? My gut says yes but I'm hoping no.

[Greybuff]

If they are good tool steel (not Chinese junk) you want to heat to cherry red bend them to how you want them, then heat to cherry red again and quench as fast as you can in motor oil. Let them cool , clean them off w/soap & water and then put them in an oven at 450 degrees for an hour and quench immediately. The first quench hardens them and they become very brittle. The second quench draws the temper and they become a tougher steel and won't break if dropped or struck. I blacksmith and this is how I have heat treated many tools that have taken lots of abuse over the years. I di this to a c-clamp about 2 months ago.

[Hawkdancer]

I will throw another question or two  into the thread.  How do you heat, straightened, and otherwise work spring (as in truck springs, etc) steel?  I don't have a forge, or smithing tools.  I'm open to any ideas, may be able to scrounge up an anvil, got a hammer, and a bad hand😀😂
Hawkdancer

[DC]

In high school, umpty ump years ago, I made a Bowie knife from a small car spring. It was about 1/4" thick. I didn't heat it at all. Just ground it to shape, being careful not to overheat it. It came out real well, took and held an edge. It had a slight bend in it cause it was a spring but you could hardly notice it.

[bubby]

Hawkdancer, a forge is pretty easy to make but you can use a cutting torch if you have access to one. Just cut a chunk of long enough well a little longer than you needthen heat it cherry red and let cool, this will soften the steel, then heat it up and beat it flat. You can then shape it with a grinder and when you get the bevel to about a dime thickness on the edge  heat it up with the torch along the edge going back and forth along the length to get it heated evenly till it is non magnetic and quench in some warm oil, veg oil works fine but it you have to use motor oil were a resperator as the smoke is highly toxic. Then when it has cooled clean it up and put it in the oven or a toaster oven at 450 for 2 hrs and then let cool, this takes the brittle out of the steel. The rest of the sanding dont let it get hot keep dipping it in water and you should be good

[PatM]

A regular old wood fire will heat steel with no trouble.

[bubby]

A regular old wood fire will heat steel with no trouble.

It will pat but you need to add air to get it hot enough to heat treat

[PatM]

Not to disagree but doesn't" Cherry Red come before the Orange? I've never had any trouble making metal even  too hot by just sticking it right in the heart of the coals.

[bubby]

The cherry red is just to make the steel workable Pat. Non magnetic to harden and a magnet is easy to find

[PatM]

I know and I've had no trouble reaching that in a hardwood bed of coals. The use of air just seems to accelerate heating.

[bubby]

I know and I've had no trouble reaching that in a hardwood bed of coals. The use of air just seems to accelerate heating.

That is the point, when forging the air helps get to temp faster, when you are repeatedly reheating while forging or normalizing before heat treat it needs to be accelerated

[BowEd]

Be nice to see a thread on forging.Many on here are into it.I hav'nt looked but I suppose there's a build-a-long somewhere too.

[PatM]

I know and I've had no trouble reaching that in a hardwood bed of coals. The use of air just seems to accelerate heating.

That is the point, when forging the air helps get to temp faster, when you are repeatedly reheating while forging or normalizing before heat treat it needs to be accelerated

Maybe if you're getting paid to do it .  For a hobbyist beating out a knife blade the fire will heat it fast enough while rests his hammer arm and mops his perspiring face with a cool cloth. lol

[willie]

too much time at temp causes grain growth. repeated reheats while forging or excessive graininess from leaving too long in the coals, calls for the extra normalizing treatment to be added to the workflow and good normalizing is hard to accomplish without a nice forge

[PatM]

This is why so few actually forge ahead and experiment even if conditions and tools aren't perfect. Paralysis by analysis.