5 Things to Do With Hot Steel, and Ideas for More.

Introduction: 5 Things to Do With Hot Steel, and Ideas for More.

About: I shouldn't have to tell you that using a dagger to undo this little, fiddly screw's a bad idea. AAAAARGH! big project ^^ so practically no chance of instructables from me till july, p'raps? maybe a bit la...

Following the puzzlement on how I made the loop on my throwing knife instructable, I thought i'd make one on the things that can be done with hot steel. I've missed a few out because i think the basics are covered here. If you want to make a bar thinner, for example, you only need to use a slight variant on Drawing out the bar. If you try this a bit, you'll get the hang of it.
The only thing you have to know is that you're changing the profile of the bar, but leaving the volume the same. You can beat it out into foil, or forge it into a sphere, but it'll still be the same volume.

Step 1: Upsetting Steel Bars

Not upsetting as in "Making Steel bars Unhappy", but reducing the length of the bar and making its cross-section larger.
Heat the end of the bar, or the bit you want to be wider to forging heat. Place the bar end-down on the anvil and hit the top, like hammering in a nail. If it cools down too much, put it back in the fire until it gets hot again, then carry on. Upset the bar until it's at the desired thickness.
You can use Upsetting to put bulges into a bar, or to make rivets, nails, bolts, ETC

Step 2: Twisting Steel Bars

You can twist steel by heating up the area you want to twist in, grabbing the steel on either side of that area with pliers and twisting it, it's as easy as that. Again, if it gets too cool, put it back in the fire.

Step 3: Hot Cutting Steel Bars

You'll need a hot cuter for this. Mine is an axe clamped in a vise.
(the axe was on fire, not long ago)
To cut a bar, bring it to the correct heat, set it on the hot cutter and hit the steel over the hot cutter. Each hit from the hammer pushes the steel down and cuts it a little more. Only cut partway through the steel. If oyu cut all the way through, you'll probably damage your hot cutter and there's a good chance that you'll have a piece of hot steel flying off into some obscure corner and causing trouble. When the steel's almost done, the hot cutter will draw heat out of it quite quickly, so you'll see a darker line on the bar. Grab the steel in pliers and pull it apart.

Step 4: Drawing Out Steel

Heat the end of the bar, or the part of the bar you want to draw out to forging heat. Hit it on one side, then turn it through 90 degrees and hit it on the other side, then turn it again and hit it some more. Keep turning and hitting it until it gets to the desired length. This is the polar opposite of upsetting a bar.
As always, don't let it get too cold.

Step 5: Bending and Straightening Steel

Fairly obvious how to do this, but i've included it anyway because it was easy.
To straighten steel, heat up the bend, put it on the anvil and hit it with the hammer until it's straight. Chances are, you'll put some smaler bends in as well, sort them out too. It's really as easy as that.
To bend steel, heat the bit you want to bend, put it over the anvil and hit it till it's bent. Again, really, really simple.

Step 6: Making Loops

I know i didn't do a good job of telling you how to make the loop on the throwing knife instructable, so here's a more complete one.
Get your steel and put a 90 degree bend in it. You'll need to put the bend about 3 or 4 inches in, or more or less, depending on how big you want the loop to be.
Put another 90 degree bend in the steel, facing the other way, so you get a step-like shape. The step-bit needs to be about an inch long.
Bend it again about .75 of an inch up from the step, this starts the loop. By now, you should have a question mark shape.
Heat up the back of the question mark shape and bring the end of the bar around, so it touches.
If needbe, or if you want to, bend it over, or straighten it.
There's more stuff you can do with hot steel, but basically, it's all variants on what you've seen here. Flattening, for example, isn't dissimilar to drawing out.
Thanks for reading.



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    38 Discussions

    Using a fuller is my favorite way to manipulate metal. I used one to make a hinge for my pizza oven.

    google , back yard metal casting and follow th' links ! there is a ton of info on furnacebuilding , forge work and , of course , metal casting !!

    so? where exactly can one buy a forge? or an anvil for that matter? i would imagine that its not something B&Q stock?

    1 reply

    In order to be cost effective, you probably ought to make a forge, actually. I hear those things are awful expensive, but my homemade concrete and steel monstrosity works just fine for cheap. As for an anvil, I don't know where to get one, but I use an old railroad rail and a brake drum and it works just fine for the stuff I do. I got both of those at a scrapyard.

    Punching, as in a hole without using a drill. Welding (not there yet, but trying). Looking good!

    6 replies

    Not got anything through which i can punch, tho i did consider it, as for the welding, i'm not sure this little furnace gets enough heat to get welding heats, but i spose i can try on smaller pieces like hacksaw blades if i get some flux...

    if you really want to punch a hole, just to punch a hole.. I've got an easy tip for you. Goto the hardware store and get a masonry nail. heat your stock, and hammer a small flat spot. while it's still cherry red, clamp the work in your vice, grab the nail and a hammer, and drive the sucker in. Once it's through, you can rotate the work 180 degrees and gently tap the nail back out. Instant hole, with NO loss of material(except to scale, but that's normal ) Don't try this with a normal nail, as they are pretty darn soft, and can be bent in wood... much less metal. the masonry nails are hardened. Welding... not liable to happen on air/propane... For flux, Borax is hard to beat. it's cheap and readily available as laundry detergent(or is it dishsoap? can never remember. A single 5lb box has lasted me forever. Also useful as a flux for casting silver/bronze by the way)

    a large propane forge can weld, its an old rumor running around that says propane forges can't weld. This guy has such a super powerful forge, he can melt chromium (melting point 3000 degrees F) He makes his own stainless steel.

    True.. with a properly constructed forge, propane/air is perfectly capable of getting welding heats. "i'm not sure this little furnace gets enough heat" and he's using naturally drafted air supply, not forced air. I didn't mean to say it was not possible at all... just not with his setup. My old natural gas forge could melt cast iron in under an hour. but it used a TON of fuel, and had a large squirrel-cage blower, and at those temps, the refractory would sag, crack, crumble, and melt. Once I got the "good stuff", it got better, but even a copula furnace with highest grade refractory still sluffs and spalls at 3000+F. I'm pretty sure there's an instructable detailing how to make such a forge already posted. If i find it again, I'll link to it, for those wanting to do more than spot heat their steel.

    Yes indeed, however, that little thing was ANYthing but properly constructed... I use charcoal now.

    basically. There's a lot of gut instinct to it, really. The only way to get a feel for it and to really understand what i mean is to get some experience at forging, really

    So is buying a knife-or not owning one in the first place. Playing with fire and knowing you can get burned is like playing baseball-you know you can be beat, but it's still fun to play.

    I don't think too many people say, "Hey, got to cut a 1/2 inch bar, time to fire up the forge!" Assuming you've got the forge going, walking away to go cut something has it's own risks.

    I'd rather not leav the forge on and wander off to do something else, for one i'm wasting gas, etc... But if i just want to cut something and not forge it, i'll cut it with a hacksaw.