Now we need to finish off the blade so it is a true and strong blade. We do this by hardening and tempering the blade. So,crank up the forge and lets get at it!

Hardening and Tempering the Blade of the Dagger

Technically you don't have to do these steps when making a knife but it is raw steel and it wouldn't be strong and it wouldn't hold a sharp edge very well. Practically not at all. We make this into a serviceable knife by first hardening the steel then tempering it a little bit. The hardening makes the steel very hard which is great, but it will be brittle and prone to shattering so we temper it to soften it up a little bit and make it flexible. This is the perfect combination for a bladed weapon.

Note this process and these temperatures are for O1 steel. The process and temperatures differ if you use other kinds of steel. They all have unique characteristics.

First Harden the Steel

You bring the temperature of the knife (O1 steel) to between 1450 and 1500 Fahrenheit. And then quench it in oil quickly. This makes the steel very hard. And it will also be very brittle. Almost as brittle as glass! Yup. So, while we want our knife to be hard we also want it to be flexible and have toughness so it can take good use.

SO, put the knife in the forge. But, don't put the whole knife right into the hottes part of the fire. Just put the handle in there and let it get heated up. Slowly, over the course of a few minutes inch that knife deeper into the fire. We do this to avoid overheating the point of the dagger. It is thin and there is very little steel so it can quickly overheat. We keep the point away from the fire for most of the time so it heats up to red hot last.

As it is getting to the red hot color check it with a magnet. Once it gets to the right temperature a magnet will no longer stick to it and it has achieved hardness temperature. You can quench it and lock it in.

There you go. The whole blade of the dagger is up to temp and a magnet no longer sticks to it. You can quench it.

This picture shows the dagger going into the quench. It is just used motor oil. You can use just about any type of oil including new motor oil, transmission fluid or vegetable oil.

Then Temper the Steel

And we do this by tempering the dagger. We bring it up to about 350-550 and this softens it up a little.

Now we want to soften it up by tempering it. We need to see the color of the steel in order to know it gets to the tempering temperature. The steel willl turn a wheat color. So, in order to see the color of the steel you have to clean the dagger. Use sand paper or emory paper to clean it. This will be very easy to do.

The Fire is way too hot to just bring the dagger up to around 350-550 so we make a little stand above the fire and set the dagger on that.

Put I put two pieces of rebar over the fire and lay the dagger down over them. This keeps it around eight inches over the fire. It will heat slower. And I moved it around/flipped it over frequently so it heated evenly. Quickly it started to turn a nice wheat color. Once that happened you quench it to lock it in.

There you go. The blade is a nice wheat color. Almost perfect. There is a tiny bit of blue on part of the edge. It got softened up a tiny bit. But it is still really good for a tempering. If you heat it too much and it turns a lot blue you might want to consider re-hardening it and then tempering it again.

Ok, the dagger is hardened and tempered. We can finish it off.

Ok, Let's continue on with the making of this dagger

The Wonder of Knifemaking

Master smith Wayne Goddard is an icon in the field of knife making. As a full-time maker, teacher and writer, Goddard works as hard to teach knife making skills as he does to acquire them. His affiliation with BLADE Magazine has brought new and interesting information, tips and tricks to thousands of would-be knife makers. Other popular titles from Goddard include The Wonder of Knifemaking (2000) and $50 Knife Shop (2001 and 2006).

Basic Knife Making: From Raw Steel to a Finished Stub Tang Knife

Learn the craft of knifemaking. 205 color images and step-by-step instructions provide for all stages of construction, from selection of the steel, to forging the blade, assembling the handle, and constructing a holder.

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