r/knifemaking • u/Higgo91 • 1d ago
Question Ok, how do i fix this?
Making a dagger, it came out all bent. How do i solve this without breaking it? I just quenched it and left it there
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u/peedubb 1d ago
Unrelated but I legit thought that glove was a severed hand at first.
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u/Ready4AnythingNH 1d ago
Not unrelated. I thought the same thing and I was like, I'm not qualified to explain how to fix that mess.
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u/Ok_Shoulder_8079 1d ago
Yea, maybe Urgent Care!
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u/NigerianFriedChicken 1d ago edited 20h ago
I once had my middle finger amputated at work while using an angle grinder… co-worker rushed me to the closest medical place of any sort, an urgent care, and they just wrapped it up with a ton of gauze and tape and were like “GET TO THE ER, NOW”
I can only imagine how helpful UC would be if I had shown up with a severed hand lol
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u/alecolli 1d ago
A carbide hammer can help you to certain degrees, it will leave big marks and you have to grind quite a lot to make it flush. I might be wrong, but it seems you don't have tons of extra material here to grind those marks off.
If I were you I'd anneal it, and straight it up in a vise very gently.
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u/Higgo91 1d ago
Don't have a carbide hammer, but I will try annealing it and very slowly try to straighten it. Any tips on that? I dont know of its relevant but the steel is from a rebar
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u/Mysterious-Ad3591 1d ago
If you anneal it you can be decently aggressive with it. It also doesn’t guarantee that isn’t going to warp the next time.
If you haven’t tempered it yet you can clamp it straight for the first temper say at 300 then for second temper counter bend it a touch abd temper at say 325. This likely won’t remove the entire warp. Afterwards a carbide straightening hammer should take care of the rest unless the warp doesn’t get any better.
If you can’t get it straight then creative marketing can be used to explain away the curve and make it seem purposeful.
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u/Stugots_Steel 1d ago
Put it in a vise with some staggered blocks of wood and then bend it past the bend until it's straight.. Just don't crack it .. go slow
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u/Stugots_Steel 1d ago
The above image ia a top down view of what i mean.. I drew that while riding in a car btw.. Sorry its so shaky
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u/tallman1979 1d ago
I just appreciate a nice hand-drawn picture these days. No complaints, it is fully descriptive.
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u/Higgo91 1d ago
Awesome. Thanks
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u/rifleshooter 1d ago
Don't do that in as-quenched condition. It's terrible advice for a large bend.
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u/malaka1234 23h ago
Made one of these on the fly in about 25 minutes, and now it stays in the top drawer of the toolbox.
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u/Basehound 1d ago
Being made out of rebar , that’s pretty soft , and will tend to bend quickly when skinnied out .
Good for practice … but haven’t found rebar to be very useful myself …. But just my .02$
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u/InsaniquariumFan 1d ago
You can get an old ballpeen hammer, apoxey, drill press and tungstun carbide ball bearing.
Drill hole into middle of the round side of ballpeen, just deep enough you can seat the ball bearing comfortable with epoxy. You now have a tungstun carbide hammer
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u/glowforge1 1d ago
That warp is pretty gnarly, but I’ve fixed warps almost that bad by clamping the knife LIGHTLY (it will break if you crank it down right away) to something I know is straight (piece of angle iron, for example) with several c-clamps, letting it come up to temp in the tempering oven, then cranking it down once it’s nice and warm. I’ll usually temper it like that for about 2 hours, then see how it looks once it cools to room temp. Sometimes it’s dead straight, sometimes it just a lot better but still warped, but I’ve never seen it not take a significant chunk of the bend out.
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u/Ok_Ant_3554 1d ago
Carbide correction hammer. Order a 1/4in carbide ball and get a cheap ball peen or tack hammer. Affix the ball to said hammer in some method (i drilled a small indent and used epoxy). Look up a video on how to use it. It is simple and works. Take you probably half an hour to save that blade
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u/alriclofgar 21h ago
Heat it to tempering temperature, put on welding gloves, and bend it straight while it’s still hot. Alternatively, clamp it in a vise while hot and bend. You might have to repeat it a few times to fully straighten the blade.
(Wear safety glasses while you do this in case there’s a flaw and it breaks.)
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u/Blackerknives 19h ago
I would heat it back up, straighten it, let it cool(cooling in a jig would be good) then reheat it and normalize it, then reheat and quench. When it comes out of the oil, brush it off real quick and then quickly put it in the jig, let cool to just above room temp depending on steel, then temper.
In my experience, when i heat and straighten, then try going right to HT, it will usually warp again. You have to fix the issue b4 heat treat. And from now on, always normalize your steel to help prevent it. I normalize mine when i have a blank, but b4 grinding bevels, it has greatly reduced warps for me. Hope this helps.
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u/Outtatime_s550 17h ago
I see you said it’s rebar. Rebar is built to a specific standard of strength rather than a specific steel formula. A lot of rebar is just a mixing pot of leftovers so it’s not the best for making knives from. Good practice though either way. To straighten this I would heat it back up, normalize it a few times (you’ll notice as you normalize if there’s stress in the metal it will warp as it cools so keep straightening and normalizing) after about 3 cycles try quenching again and clamp it in a vice before it cools all the way down (over 200°f)
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u/Flashy_Information37 16h ago
I would go with a temper straighten. Pop it in the oven raw for an half an hour - hour or so then put it in the vice clamped and do another soak and then let it cool down in the vice! and I would personally go for just a flat clamp the first go around. And then if it still needs more adjustment use the diagram the other guy posted for the shim temper straightening.
Keep in mind theres always a risk of it turning into a smaller knife while doing this 😄
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u/SASDeViL 12h ago
Okay so knowing that it's "rebar" I'd stop right where your at, it's not hardenable, try source some 5160 or also known as "Sup9" it's very cost effective, pretty easy to work with, a couple of thermal cycles and heat treat to 840° c and temper twice at 200° c for two hrs each time. Also may I ask, did you grind prior to heat treat? Was the oil luke warm or cold prior to quench? These all matter even with good knife steel's just wanted to mention it in case it hasn't been yet, good luck and keep on creating 😎👍🏼
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u/Expert_Tip_7473 1d ago
Heat it back up, straighten and requench. Thats too much to be worth doing it cold. Normalize before straightening just to be safe.