Once the blade is hardened and tempered it can be polished. Please check out our short youtube videos on knife building, making an easy fire pit forge and the hardening process.
Check out this easy to make Knife Necklace crafted from 300 series stainless steel.
For this project we are going to use an Files and a disc grinder with an assortment of cutting and grinding discs to create a set of durable Throwing Knives.
After the blade is formed and smooth. The blade then has to be re hardened. Bring the blade back to cherry red and a non magnetic state. Then instead of letting it cool slowly, this time quench the hot knife quickly in oil. This will make the steel very hard but also brittle. The last step is called tempering and will make the blades less brittle. Put the blades into an oven @ aprox 375 degrees for 2 hours. Then let it cool overnight in the oven. This tempering process will make the blade strong and less brittle.
Use cut off wheels to cut the rough outline of the knife. Then grinding wheels to bring it into the desired shape. Next switch to a flap disc sanding wheel. Start with a rough disc like 36 grit and smooth out all of the high or rough spots. With finer sanding discs the blade can be brought to an almost finished polish. It may take some time but grind away all of the lines from the files teeth.
We are using files as the raw material for this knife project. Files are very hard but also very brittle. The first step is to anneal the steel which brings it to a softer state. This makes it much easier to cut and grind into the desired shape. This can be done in a forge by bringing the material to a cherry red and making sure it has reached a non magnetic state. Then let it cool down slowly. Do NOT quench the hot file in oil or water. Let it cool slowly. Without annealing it would take substantially more time and grinding wheels to achieve the same results.
Throwing Knife Set made from Files
DIY Easy Knife Making, learn how to soften, cut and shape steel into a finished knife using only simple tools like a disc grinder.