In this part of the tutorial we grind out the bevels in the blade and harden/temper the blade.

Part1 (the beginning) of this tutorial is here.

Now we are going to grind (file) the bevels in the knife. This means filing the edges at an angle so they meet in the middle. Here is a look at the side of the knife. I have drawn a black line right down the midddle. That is where we bevel to.

It doesn't have to be exact, and we don't really want to bring it all the way to a sharp edge at this point because that makes hardening and tempering difficult. Leave a little bit of leeway there.

This picture shows filing at an angle. This is how you create the bevel.

You have a lot of leeway in how far you grind the bevels. The important thing is that top and bottom meet along the center of the thickness.

This picture shows you the beveling in progress. I still have a long way to go but it is looking good.

More beveling, keep at it!

HARDENING AND TEMPERING

Next we need to process that steel by making it knife worthy. We do this in two steps. First we raise the temperature of the steel to about 1450-1500 Fahrenheit. This changes the composition of the steel. Once it gets to that temp we quench it in oil. Note that this temperature is just for O1 steel. Other steels need other temps.

So, put it in the forge fire, or heat it with a torch. We are mostly concerned with the blade section of this knife. It isn't critical to get the handle part to this temp.

You can eyeball it. When the knife gets to red hot about like this it is close to ready. This needs a little more. You can check it with a magnet. A magnet will stick to the steel. Once you get it to the right temperature the magnet will no longer stick to it.

That would be the right temp. Quench it in oil!

This picture shows that we overheated it just a little bit. This is evident by the patches of yellow hot. But we can go with this.

Go ahead and quench it. Be careful, it is going to flame quite a bit.

That is used motor oil. You can use old motor oil, transmission fluid or vegetable oil.

Once it fully cools it is hardened. It is very hard, and well, too hard. It is now brittle. So we have to soften it back up so it has some strength to it. We do this by tempering it. We raise the temperature once again but this time to only around 350-550 fahrenheit. This softens it back up a bit.

We can't use the magnet for this. We do this stage by the color of the steel. We want to heat it up evenly and slowly to a wheat color.

The knife, after hardening has a lot of black scale on it so clean it off with emory paper. It cleans fairly easy. This way we can see the color change.

We heat it slowly by propping it a few inches over the fire. This way it heats slower and it heats to a lower temp. Move it around, be cautious of the tip of the dagger getting too hot and turning plum color. Plum color means we over softened it.

Flip it, turn it a bit, re position it, and keep an eye on it so it heats evenly and slowly.

It is just about perfect with a nice wheat color, and you can see there is a tiny bit of plum sneaking in so lets quench it now and the tempering is done!

Let's continue with the tutorial

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