how to forge a knife

how to forge a knife

Part 1 Part 1 of 3: Forge the tip

Heat the metal in a forge or in your metal melting furnace. The appropriate temperature varies, but an air blown charcoal fire will suffice.

  • A piece of 01 steel is ideal for this project.
  • You should always wear eye protection and gloves when working with hot metals.

Check the color when the metal is hot. The steel should be at 2,100 to 2,200 °F (1,150 to 1,200 °C), and will have a yellow or straw color.

  • Use forging tongs whenever you want to remove metal from the flames, as it will be very hot.

Forge the blade to a point. Place one end of the hot steel on an anvil while holding the other end with forging pliers. Then, use a round hammer to tap one of the corners of the hot steel end into the shape of a knife point. The flat side will be the edge of the blade later, and the curved side will be the spine when you’re done.

Part 2 Part 2 of 3: Flatten the blade

Leave room for a spike. The tang is the part of the knife that goes on the handle. Leave about 2 inches (5 cm) or more on the end of the steel opposite the dowel point.

  • Use a ruler to measure the end of the metal. Then, hammer in a small mark where the dowel begins for reference.

Set a sheet. Reheat the metal. Then hit rows with the hammer on the blade to narrow the steel and give it a distal taper. Work on both sides of the sheet to prevent warping.

  • Knives generally have a distal taper, which means the blade tapers as it gets closer to the point.

Hammer the flat edge to make the bevels. Hammer the flat edge of one side of the sheet. Then flip the sheet over and hammer the flat side of the other side. Continue like this while working on both sides so they are even. Keep in mind that hammering the bevels will cause the blade to bend toward the spine, which is normal.

  • The bevels are the slight slopes on each side of the blade that go towards the cutting edge.

Prevents sheet from crushing or bending. Both of these problems cause inclusions that weaken the blade.

  • If you notice the metal folding in on itself when you hammer in the edge or thorn, place the blade flat on the anvil and hammer the edges down so they are flat again.

Part 3 Part 3 of 3:Strengthen and sharpen the knife

Heat the knife red hot three times to anneal it. Allow it to air cool between each heat until the red color disappears. After the third time you heat it, allow it to cool on the fire overnight. Cooling it very slowly will make it softer and easier to file.

Sand the blade to shape and smooth out any rough spots. Run the edges and sides of the sheet back and forth over sandpaper to smooth them out.

Go back to heating the steel and soaking it in motor oil to harden the blade. You should only submerge the metal vertically. Any other angle, no matter how small, will create bubbles around the metal, causing a warp that you will have to reforge.

  • Leave the steel in the oil for 30 to 60 minutes.

Place the knife in an oven for one to two hours at 250 to 350 °F (120 to 180 °C) to temper it. You can also leave it in a warm place covered with some coals, like a makeshift brick box.

  • Soaking the blade in motor oil makes it harder, but also more brittle, so it’s important to temper it afterward. Tempering will make the blade harder and less brittle.

Put a handle on the knife. You can punch holes and dowels into the dowel, or wrap cable or wire around the dowel. You can also make a pointed dowel, put it in a block of wood and file the wood to shape.

Sharpen the knife with a fine file and then with a whetstone. Lastly, use a leather razor softener with polishing paste to remove burrs and have a nice sharp edge.

  • Start with the coarse grit side of the whetstone. Hold the knife edge against the stone at a 22 degree angle and run the blade forward across the stone 10 times on each side. Then repeat with the fine grain side of the stone.

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