There is nothing worse than not having the right tool with you! You are unlikely to find yourself in a situation where there was nothing left to do but forge a knife with your own hands, but who knows what will happen in the future? No one is immune from this, and if you suddenly find yourself in a similar situation, you will remember this article with gratitude!
Steps
Step 1. Preheat a piece of metal in a forge or in your furnace for heat treatment of metals
The temperature depends on the specific metal, but in any case, a coal flame blown by an air stream should be enough for you.
Step 2. Take a look at the color of the heated metal
The steel must be heated to a temperature of 1150-1200 degrees Celsius (2100-2200 degrees Fahrenheit), and at this temperature it will glow with a straw yellow color.
Step 3. Pierce a piece of metal into the strip so that the thinner edge of the strip will eventually become the tip of the knife blade, and the rounder edge will become the butt of the blade
Step 4. Leave room for the shank (part to be inserted into the handle)
Leave about 5 cm or more from one end of the blade.
Step 5. Open the blade, passing along it with a one and a half kilogram blacksmith's hammer (the optimal weight depends on your size and strength); apply light blows from the base to the end of the blade, forming a wedge that is thinning towards the edge
Strike both sides of the blade to avoid bending the blade.
Step 6. With hammer blows, form bevels towards the tip
In this case, the blade will bend so that there will be a concave surface on the side of the butt.
Step 7. Try not to allow the blade to bend or flatten out with a thickening in the middle, as this will reduce its strength
Step 8. Remember, while the shape of the blade is far from final, you can heat it three times in the oven until it is red hot (above the magnetic transition temperature), then cool it in air each time until the metal stops glowing
After the third annealing, let it cool overnight with the oven. This very slow cooling will soften the metal, making it easier to file further.
Step 9. File the blade, removing bumps and roughness
Step 10. Again heat the metal above the magnetic transformation temperature and then immerse it in a vat of oil, thus hardening the blade (there are steels that are hardened in oil, water, or air)
By immersing only the cutting edge in the liquid, you will harden it, leaving the back of the blade soft, which will increase the overall durability of the knife.
Step 11. Place the blade for an hour or two in an oven heated to 120-180 degrees Celsius (250-350 degrees Fahrenheit) for annealing (this is called tempering after quenching)
Step 12. Attach a handle to the blade (drill holes in the shank and attach wooden plates to it with a rope or wire, or sharpen the free end of the shank and stick it into a wooden handle, then bringing it to the desired shape with a file)
Step 13. Sharpen the knife with a fine file and then with a sharpening stone
Finally, use a strip of leather smeared with polishing paste to remove the remaining abrasive particles and finally sharpen the blade.
Advice
- Forge the metal when it is red-hot, but try not to overheat it to the point where a large number of sparks will fly out when hammering.
- Work the blade equally on both planes.
- Take your time. As a rule, the more time it takes to make the knife, the better the knife turns out.
- Do not touch hot metal, let it cool down.
- If you do not have at least a seasonal blacksmith experience, do not expect that your first knives will turn out to be good; you will need months or years of training.
- Do not hit the metal too hard with the hammer, or you will dent too much.
- Before working on the anvil, it is better to cast the blade blank using a clay casting mold; it will be easier to shape and sharpen such a workpiece.
- If you prefer the simplest way, take a metal plate and sharpen its edge on a grindstone or something else.
Warnings
- If only the cutting edge of the blade is hardened (step 9), there is a small chance that the blade will warp.
- Metal processing is a very dangerous business.
- You will have a sharp knife, so don't use your thumb to test the edge for sharpness!