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I Forge Iron

Leaf Spring

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I am in the process of learning the art of the blacksmith. My main interest is in blades. I would like to make knives, and then, after ALOT of experience, a sword. I went to the junkyard and got some leaf spring.
My forge has handled everything well, thin carbon steel knife blades getting to forge temps very quickly (If i get it heated up right. That is quite the project itself :) ) However, these leaf springs are THICK, almost an inch. I find the task of getting them very hot rather difficult. I have only been able to get them in the red-orange area.

Is my failure to get them any hotter a result of the harder steel or the thickness?

I run a basic forged powered by a blow-dryer and the fuel used is cowboy charcoal. I would love any suggestions or sage advice.

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It's not the makeup of the steel but the mass. You need some more fire.

The charcoal will work just fine but you need a lot more blower. A hair dryer won't push air against much back pressure (deeper pile of charcoal). Not even close. You can buy yourself a proper forge blower or use the blower from a vacuum cleaner or a clothes dryer. These will do you a much better job.

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One inch thick leaf spring, WOW. I wonder what a spring like that came from. As Rich says, try to find some thinner spring material. You should be able to find something that is more like 3/16" thick without much trouble.

Lol well my current plan is to hammer the heck out of it while it is red-orange until it gets thinner.

The problem for me is that I do not live in an area where a forge blower is easily accesable. If anyone could get me a link to some places to buy online, or even a place to get a bellows, that would be cool. But otherwise I think im stuck with a hair dryer.
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Yes, I've never seen leaf spring that thick. The typical leaf spring is just a little more than 1/4" thick and 2.5" wide, and that is tuff stuff. Actually, I believe red-orange is hot enough for forging. The problem is the size not the heat. Get an 8 pound hammer and choke up, get a striker, whatever. People don't genearlly like to hand hammer 3/4" steel of any type, but if that's what you have, just know that it's going to take a while. After you get it started to move a little, it'll go.

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However, these leaf springs are THICK, almost an inch. I find the task of getting them very hot rather difficult. I have only been able to get them in the red-orange area.

They probably came off a semi or a dumptruck, if so, they are likely AISI 5160. This steel is a little stiff under the hammer unless you get it good and hot, in the yellow range. Instead of trying to heat the whole spring up perhaps you could cut a piece off, your forge should have no trouble getting it up to temperature if it were smaller .

Typical Chemistry
Carbon 0.50%
Manganese 0.80%
Silicon 0.30%
Chromium 1.00%
Vanadium 0.15%

Typical Applications
Chisels Punches
Fixtures Pump Parts
Machinery Parts Splines
Piston Rods Springs
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Luke, What the other guys said- use smaller stock if you can find it. Leaf springs are a very common easily found item, in the normal automobile size.
Even these are very tough stuff which can be hard to move.
Thick / heavy iron likes to take its time getting up to forging temps, evenly heated throughout. Its easy to burn the outside without the inside getting close to where you want it to be.
Charcoal for fuel? Try using a LOT more of it. Perhaps your fuel is burning away? Charcoal is nice to use but it goes quick so have a LOT of it heaped on the hearth and keep your fire fed.
Try coal.
there are blueprints for making a blower from a clothes dryer, or use your own ingenuity. Small squirrel cages can be had on fleabay for 10 or 15 bucks.
Join your local abana affiliate group.
Good luck. Dan:)

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It may always be possible to find stress cracks in used leaf springs and these can occasionally manifest themselves in the final product. I have not had this problem in the past but have been told it does happen. If I did notice it, I would take a right angle grinder to the stock prior to forging and remove 20-30 thousandths per side. This should get rid of anything you might encounter. You can heat the stock to a bright cherry red and visually look for cracks because they will become apparent due to differential movement.

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In my opinion ..you should try smaller pieces ( if you don;t want to build a bigger forge)

small pick up truck springs. ..that you have to anneal first
to do this ..prepare a bonfire big enough so that the coals left over will completely cover the springs. .

arrange the wood with the springs at the center. ..and light. .when all that remains are coals .and burning embers. . .cover the springs. .uniformly .with the hot coals. .and cover the coals with a layer of dry sand ..
leave till the second day ..
after you remove the springs from the pile..you shouldn't be able to hold them with bare hands and if u spit on em . .ure spit should sizzle.

then you can bend and cut and grind at them, ,so you don;t have too much material to heat up in the forge. ..They will also be easier to forge.

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hhmmm, 1 inch huh, well you got a heck of a paper weight, lol!
I can't add much to what the others said, but, you do need auto springs,
also a squirrell cage blower from a car or truck will boost your air.
I use the exhaust from an old shop vac, it works great!
good luck and happy forging!

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on my first coal forge i built , i bought an old electric leaf blower for 5 dollars at a flea market rigged it up with some cheap sheet metal i either fabricated or bought from home depot , it was a universal motor so i used one of those router speed controllers to control the speed of the blower. It worked well.
since then i have just a fasco squirrel cage blower with two speeds
my 2 cents

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