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I Forge Iron

dump truck leaf springs


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Ive heard from a few reliable sources that heavy leaf springs like that are often 6150 or 9260..
Also from the book "machine elements" leaf springs in this heavy use/abuse catagory may well be 6140,6150,9250 or 9260...
Impossible to tell really but Id bet its a high alloy tough steel like one these I listed..

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These kinds of questions come up frequently, but without a scientific analysis no one can tell you what you have for sure. Rule of thumb, if it made a good spring, it should make a good larger sized blade such as a camp knife, bowie, or other chopper. Edge holding will probably not be as good as other higher carbon steels but for these types of blades that is less critical imo. I have made a number of blades from recycled springs of unknown composition; i just heat treated as if it were 5160 and they have come out ok. I do not recommend water quenching, use oil.

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I took a couple big thick chunks of similar leaf springs and made a couple stout hot cut hardies with 'em. Hydraulic press was definitely helpful in forging down the hardy shank. The edges took some real heavy hitting with a 3# hammer to shape 'em - just make sure they get and stay hot clear through and hit 'em hard or you'll just be moving the outer portion of the metal.

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Glad someone else mentioned these springs. I have a friend that owns about 25 trucks and the mechanic there is a best friend. So. I get my choice of anything that hits the scrap Pile.
Those big trucks sure have alot of material that you can use off them. Springs are the most likely to Be changed after getting broken. But all kinds of races and bars come off these dudes.
You definitely Need a torch to rough them.down to size. Or you'd kill yourself. They make good camp.tools, like axes and hatchets. If any have pictures of some things they've made using dump truck parts. Please show them. For me.
I Got more material than I could ever use. The pile is 6 foot tall. I.give all.my stuff away that I.make. but Hope to.build a tire hammer this spring. So gonna start making something different outta. All these parts.
Actually. Some scrap.pieces are beyond me. They are to thick And hard. But after the hammer is built I.am gonna get rolling more. Just curious as to.What y'all have came up with. I
Outta this stuff. I.am rarely around other smiths And kinda get in a rut on.stuff.
Enjoy making tooling from this stock. Holds up well. Just looking for some ideas that I can do with It.

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I made a bic-iron out of a heavy truck spring. I cut the leaf at the bolt hole and fullered that end to fit my anvils. Next, I split the opposite end and opened the legs to about 6 inches of the hardy, describing a short 'T'. Then I drew out each leg- one a tapered round cross section and the other a tapered square cross section. Each leg is about ten inches long, sharing a short flat section at the hardy. I gound out all the hammer marks and polished it. I did all of the forge work with a 5 1/2 lb hand hammer. It was a lot of work but a good tool. That much steel and a heavy hammer kept the thing at a working heat longer than my stamina lasted. I forged at a yellow heat and reheated the steel slowly so I could recover before the next bout.

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Note that dump truck springs are usually a LOT of work to get into a usable size. If you do not have a powerhammer you may want to put them aside for a bit till you get one and find some stock closer to final thickness to use.


Whats wrong with a 1/4th to 5/8 inch thick knife? the only thing its really overkill for is small knifes(like the 3/8th inch thick skinner I made a while back.), as long as you're making a beastly Ganga Ram Kukuri or a good hefty Arkansaw toothpick you should be free and clear,

Notes: try and get your hands on some of the florescent dye used to check welds for micro fractures, I tryed to make a Kukuri out of a train leaf-spring and it shattered partway through the manufacturing process due to existing fractures. Also extremely important, If you intend to weld or flame/plasma cut the steel remember to preheat to at least gunmetal grey [650°F or 343°C] though I'd take it all the way to black/dark red, High carbon loves to heat shock fracture, especially thick stock like this.
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Talk with real users; massive heavy blades tend to stay put away compared to ones that will ride your hip all day without pulling your pants down. If you need a hatchet why not carry a hatchet?

One of the most refreshing students I have had was an ex seal; I was worried when he wanted to make a knife as so many folks seem to want a sharpened crowbar; but when it came time to start one with him he wanted a 4" blade. As he said "He had never run into anything he couldn't deal with with a 4" blade..."

I study medieval metalworking including arms and armour and folks are generally flabbergasted at how light and FAST medieval weaponry is; I have "Knives and Scabbards Museum of London" and with around 310 medieval blades in it I don't think any of them were even 1/4" thick---and none of them were double edged either!

You can make what you want, I too have some real poorly designed blades in my past before I learned to look at what works and has been proven in over the last 1000 years of folks staking their lives on their blades.

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