How to forge your own knife

i think that it’s important that people who are interested in DIY projects learn how go about learning things. That may sound confusing, but what I mean is pretty simple: it’s more important that someone learn how to come up with their own projects without any instructions and keep with them until they succeed.
The first thing to know about forging knives is the names of the basic tools — the forge is where you make things hot, the hammer is what you use to shape things along with the anvil, which is a kind of metal platform. You use tongs to hold the metal when it is heated up.

Before you can forge anything, you need to get something to forge. Generally, car springs work well for this kind of project, but if you want to get really hardcore, you can buy metal from a mill/foundry somewhere. There are plenty of articles on the different properties of various alloys and where to buy them from, so I’ll leave you to explore that aspect of the art.

So once you get a hold of some metal then you will need to build up a fire in your forge. Don’t have a forge? No problem, you can make one with a hairdryer, an old barbeque, some pipe and clay. A forge is basically just a heat resistant box with air being forced into the fire through a pipe. There are a ton of great plans and instructions available online.

After you have a good fire going you heat the metal. To avoid forming scale on your metal, you will want to bury it deep in the coals until it gets to a cherry red colour. Avoid overheating, which will cause the metal to spark when you hit it — that means that the metal has been burned and can no longer be used; you can cut burned parts out with a hacksaw after the metal cools.

To begin the actual shaping of the blade you will want to hot cut the point, that is, you heat the metal up then drive a wedge into it to cut pieces off. After the point is cut in, work on forming the tang. Hit the metal from where you are forming the base outwards, draw it thinly enough that a handle can be easily fit to it, but not so thin that it is creates a weak point.

Next is one of the trickier parts: you forge the blade. Work carefully, striking the corners of what will be the edge, flipping it over and striking it equally on either side. Hold the blade at an angle to the anvil so that the bevel is formed on both sides, and work your way from the tip to the hilt. Stop once the edge is about 1/8th of an inch thick and allow the metal to cool.

Heat the metal as evenly as possible and then allow it to cool again very slowly; this is called annealing and it relaxes the metal in a uniform way. In the next part, the one that can be the most interesting, you heat the metal up to a cherry red, then plunge it tip first into a drum of oil, this cools the steel rapidly and causes it to harden. This is the time when any flaws will be revealed; sometimes there can be some bad warping, in which case you have to reheat, straighten then attempt to quench the blade again.

Now comes a fairly difficult part: the tempering. Soak the knife in some vinegar overnight and sand off the scale so that you can see the metal clearly. This is a very important step. Now heat the blade slowly from the spine and look for a change in colours — that’s the metal losing some of it’s hardness and becoming less brittle. You want the blade edge to be a dark straw color, the middle of the blade to be a light blue and the spine to be a light purple colour. This is best done very slowly, and once the desired colours are obtained, quench the blade in either oil or water to stop the process.

Now it’s time to grab a file and begin to shape the edge. Most machines will overheat the steel and should thus be avoided unless you do more research into which machines to use and how to properly use them. Now you clamp down the blade and file down the edges equally on both sides. After this step you can sharpen the blade the same way you sharpen a regular knife.

I left out the handle making as it is a different art altogether and quite an indepth one too. I encourage anyone who attempts this to do their own research into how to make a good knife handle. There are many great sources online that describe this process much better than I could.