How to Forge a Knife

There's nothing worse than being unequipped! Now, that isn't to say that you'll ever be in a situation where you have no choice but to forge your own knife, but who knows? It could happen, and if it does you'll be thankful that you read this!


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    Heat the metal in a forge or your own personal metal working furnace. Proper temperature varies, but a charcoal fire with introduced air is sufficient.
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    Check color when heated. The steel should be 2,100 to 2,200 °F (1,150 to 1,200 °C) which is a straw or yellow color.
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    Forge the blade to a point so that the flat side will be your blade edge and the curved side will be your spine when finished.
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    Leave room for a tang (the part in the handle). Leave about two inches or more on one end.
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    Establish a blade, by repeating rows of small taps with a three pound sledge (best weight will depend on your size and strength) in long rows up the blade, narrowing the steel making the distal taper. Work on both sides of the blade to prevent it from distorting.
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    Hammer out the flat side to make the bevels. Note that doing so will cause the blade to bend back on the spine.
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    Try to keep the blade from mushrooming or bending over itself, as this will cause inclusions weakening the blade.
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    Remember, when it is a rough blade shape, you can anneal it by bringing it to this red hot nonmagnetic temperature three times and letting it air cool till all the red is gone. After the third heating, let it cool in the fire overnight. Cooling it very slowly will make it softer, easier to file.
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    File to shape and even up any uneven spots.
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    Bring back to nonmagnetic and dip in a vat of oil to harden the blade, (there are oil, water, and air hardening steels). Dipping only the cutting edge will provide a hard durable cutting edge but leave the back flexible, thereby increasing the overall durability of the blade. Only dip the metal vertically, any other angle besides being a few degrees off will create bubbles around the metal, causing warping and you to have to reforge.
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    Put it in an oven for an hour or two on 250–350 °F (121–177 °C) to temper it. You can also leave it in a hot covered spot with a few coals, such as a makeshift brick box.
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    Handle it (either drill holes and pin scales of wood, wrap with cord or wire, or make a pointy tang and put in a block of wood then file it to shape.
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    Sharpen your knife with a fine file, then with a whetstone. Finally use a leather strop impregnated with polishing paste to remove any burr and leave a razor sharp edge.


  • The anvil needs to sit at a certain level, right at the smith's knuckles, by not adjusting the height properly you can suffer from low back pain and not being able to forge correctly.
  • Don't expect your first knives to be any good unless you are already skilled at blacksmithing, it takes months or years of practice to do well. To learn, make simple tools like hammers, punches, nails, etc. This could also help from having embarrassment at forging classes when a knife turns into a spoon.
  • Only work the metal when it is red hot or hotter, but try not to get it so hot you see sparks spraying from the metal. Some metals start to lose their chemical bonds and will be brittle when cooled, for example, iron and cast iron.
  • Take your time. Knife making is something that gets better with the more time you put into it.
  • Work the metal equally on both sides to make it uniform.
  • If you want to go it the easy way, just use thin metal no greater than the thickness of a brass key, cold forge it (forging without heat) to any shape, and file an edge and then sharpen it on a whetstone or any fine grinding surface.
  • Don't hit the metal too hard with the hammer, even if the face is flat, you will put a big ugly divot in it.
  • Do not use any hazardous materials, even acid to clean, shape, and plate metal. Melting lead ingots are enough to cause serious long-term health issues, if you are unsure of the material, clip off a very small amount and melt it at different metal temperatures. Wear proper breathing masks and eyewear while testing for unknown materials.
  • Choose metal that will hold a long life, ultimately, steel is the best metal to make any tool or product, but can be expensive and hard to forge. Do not use more softer metals such as tin, zinc, and so on. If you only have small increments, smelt them together but be careful around each metal's melting and boiling point and as well as mixing them.
  • It is easier if you make a clay mold and cast the metal before you use the anvil so it is in shape and easier to sharpen.
  • Don't touch the metal until it has cooled to a point where you can see the color of the metal that you've started with.


  • When quenching only the edge of your blade (step 9) there is a chance that the blade will warp.
  • Do not set tools near or in the forge for more than 10 seconds, and do not touch them with your hands, let them them air cool.
  • Metal working is highly dangerous, be smart, focused, and use caution when around the forge. If you see a piece of metal that you know you did not cool, used the pliers, not your hands.
  • Your knife will be sharp, so don't test it on your thumb!

Things You'll Need

  • Metal
  • A Furnace
  • Tools (ie. hammer)
  • Experience with metalworking
  • Sensibility
  • Possibly a medical professional

Article Info

Categories: Metalwork and Wire Projects