In this part of the tutorial we finish off the knife by heat treating it and polishing it.

Part 1 of this tutorial is here

Heat Treating the Knife

Now, we need to heat treat the point and bevels of the knife. No need to treat the rest of the knife. But it is important to treat the point so it will be strong and durable and so it will hold its point and sharpness.

First we harden the tip by heating it up to red hot with a torch.

Once it gets up to red hot you quench it in oil. That is just plain old motor oil in the can. And use a coat hanger because the steel is hot and dangerous.

Quenching it like this locks it into its hardened state.

But, having it this hard isn't necessarily a good thing because it is also brittle. So, we need to soften it back up a little bit. This way it has some flexibility and it won't shatter or crack with use. So, wipe the oil off and use some emory paper to clean it up. Get rid of the colors and get it back to its steel color.

Now, we soften it up by heating it again. But this time we heat it gently and slowly only to a lower temperature. And we can do this by observing the color of the steel. Keep the torch on low and keep it a bit away from the steel, spreading the heat evenly. And watch as it turns to a beautiful wheat color.

That wheat color is the exact right temperature for us.

There you go. It looks fantastic. It has a beautiful wheat color. And notice how the tip is starting to get just a little toward a plum color. We don't want the plum. That means it is getting a little too hot. So, keep the plum to a minimum.

Once you get it to a nice wheat color dip it in the oil again to lock it in.

So that's it. Your knife is hardened and tempered. It is ready for cleanup and polishing.

You finish off the knife by polishing it. You do this by going through a series of grits with emory paper. You start with a coarse grit like 80. Then you move through progressively finer grits like 150, 220, 400 and 600. I went as far as 600. But you can go even further if you want a mirror finish on your knife.

That's It! Your throwing knife is complete.

Knife Throwing: A Practical Guide

A concise, informative book on "the sport of the pioneers". Knife Throwing includes beginning and advanced throwing techniques and covers everything from home practice to hunting methods with accurate instructions. Readers will learn how to hurl hatches, tomahawks, the Gurkha Kukri, Bowies, and other knives.

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