ABS master smith Don Fogg demonstrates how to
forge a blade at an Ashokan Seminar. (photo courtesy
of Tim Zowada)

Forging is a great way to shape a knife blade. Though it is an additional step compared to “getting a bar of steel and grinding away everything that doesn't look like a knife,” forging is an enjoyable and rewarding way to get the fundamental blade shaping done. Basically what you do is, “get a bar of steel, heat it up and hammer on it until it looks like a knife.”

Forging does not necessarily result in a better knife than one made by the stock removal process. In the “old days” we heard that you were improving the steel, and making it stronger, by forging. In fact, it is easier to decrease the quality of the steel by improper forging than to improve it by any significant extent. These days, most steel comes in pretty good condition from the mills. Yet, forging blades still offers some important advantages.



This is how the steel looked before the author
“hammered on it until it looked like a knife.”
(Nathan Zowada photo)

Forging blades is just plain fun. It is kind of like working with hot clay. It is possible to create complex shapes and tapers that would be difficult, or nearly impossible, by stock removal. Complex integral shapes come to mind. By doing your own forging and annealing, you have complete control over the internal structure of the steel. You can also recycle old steel or use odd-shaped stock for your blades.

Please understand, I strongly suggest you buy your steel new from a known distributor. But, these days, one of the best sources of L6 offers it in round stock only. When you have a fire and a hammer, round stock isn’t a catastrophe, it is only an inconvenience.

Forging blades does have a few drawbacks. It is a new skill to learn. While you learn, you will make more junk than have good results. Yet, if you enjoy forging, it will all be part of the journey. With the possibility of decarburization, overheating, and cold forging, it is truly possible to make your steel unsuitable for knives.

Finish grinding a forged blade is a little trickier than doing a regular stock removal blade. Forging then finish grinding is also slower than pure stock removal. If you consider the time spent both forging and finish grinding simple blades, a good stock removal maker is always faster. In forging, there is also more equipment to buy or make.



This is how the steel looked before the
author “hammered on it until it looked
like a knife.” (Nathan Zowada photo)

With all that said, I think you can still tell where my loyalties lie. I have been forging for 28 years and making damascus for 25. Yet, sometimes there is a conundrum. Lately, I have been doing stock-removal-type grinding for pocketknives and razors made from damascus that I have forged! Oh well, it’s all fun.

First Things First

To forge blades, first you will need a forge. Forges can take many forms and burn many types of fuel. In the beginning, just keep it simple. You will need to learn both temperature and atmosphere control. It’s no big deal, just another skill. For the beginner, the propane forges are easier to learn how.

You will also need an anvil, or something to take the place of an anvil. With anvils, bigger is better. A few years ago, I was standing next to my son while he was forging on my 150-pound anvil. I noticed that I could feel every hammer blow through my feet on the ground. That means he was wasting energy moving dirt and my feet, energy that could have been moving steel. I now have a nice 500-pound anvil. Substitute anvils can be made from a chunk of steel, railroad rail, or even a rock. You just want it as big, flat and smooth as possible.

You will need a hammer or two. Initially, a 1.5-to-2-pound hammer is about right. Most smiths prefer a cross-pien style. The hammer face should be very slightly crowned with smooth radii on the edges. Later, a 4-pound hammer will be handy for moving steel fast.
The types of steel used for forged blades vary widely. It is best to start with the simple oil- or water-hardening types. Examples such as 1084, 1095, O1, W1, W2, 5160 and 52100 are all fine for starters. You can use high-alloy and stainless steels once you gain a higher level of experience. The best thing to do is get a copy of the manufacturer’s specification sheet on each steel and follow what it says.

Forging Practice

While forging blades it is important to keep track of a few things. If you are careful, you will end up with a piece of steel that is capable of being finish ground and heat treated into a good knife. You will want to closely monitor both the forging temperature and atmosphere inside the forge.



The beveling is halfway done.
(Nathan Zowada photo)

Most smiths judge the blade temperature by eye while forging. That is where experience enters the equation. You should have consistent lighting in your forging area. That way you will get used to how things look in your shop on a daily basis. If your shop is bright one day and dim the next, it will be very difficult to keep things under control. Dim, subdued lighting is best. As a result, you will find that most forging shops are relatively dark places.

Some smiths will use a pyrometer and thermocouple in their forges. That is fine as long as you remember you are reading the forge temperature and not necessarily the blade temperature.

In general, you will want to heat the blade to a medium-to-bright-orange color for forging. That will correspond to about 1,900°F. Avoid both yellow and white. If your steel is white with sparks coming off it, throw it away and start over.

As the blade cools while forging, it will gradually get darker. It will reach a point where you will see dark “shadows” forming in the blade. That is the time to stop and return the blade to the forge.



The bar has been pointed, tapered and
beveled at this stage. All that’s left is to
forge the tang. (Nathan Zowada photo)

Forge atmosphere control is important in keeping the carbon content of the steel where it should be. In general, for most of the simple steels, you will want the forge atmosphere to be neutral to slightly oxidizing. You will lose some iron due to scale. But, you will keep more carbon. I know this sounds backward but read Tool Steel Simplified (pages 437-445) [1] for more information.

In gas forges, the atmosphere will be neutral to slightly oxidizing when you adjust the air so that the forge is glowing its brightest. If you turn up the air too much, the forge will get cooler. If you turn down the air, the forge will get cooler. For coal or solid fuel forges, you will generally place the blade to be forged level with the top of the fire pot.
Because of decarburization, it is a good idea to forge blades at least 0.020-inch oversize on all dimensions.

How And Where To Hit It

While forging, you want to avoid hitting the anvil with the hammer. You want to hit the steel, supported by the anvil to shape it. So, when forging points or bevels, try to work near the edges of the anvil. Use the middle of the anvil for straightening and flattening.
Do not be afraid to hit the steel hard. You want to work as quickly as possible. Every time you heat and hammer the steel you run the risk of messing it up, so hit it hard!

Here is the forging progression I usually use:

Step 1) Forge the blade tip and taper: Working on the far edge of the anvil, forge a point on the bar. You will also have to forge the tip on its side to keep it from getting too thick. Taper the blade’s thickness from the guard to the tip, both at the same time;

Step 2) Forge the blade bevels: Start at the tip and work back toward the tang. It will take several “heats” to get this done. Lay the blade on its side so that the blade edge is flush with the edge of the anvil. Use a glancing blow to taper the edge. Flip the blade over and forge it on the other side. Try to forge evenly on both sides of the blade.

As the bevel begins to take shape, the tip will curve up. You can forge it back down while it is hot, or plan for it while doing Step 1. While forging the tip, have what will become the cutting edge flat or even slightly concave. When the tip rises during bevel forging, it will end up looking less like a scythe and more like a knife.

Step 3) Forge the tang: I admit, I usually use my steam hammer for this. For a full-tang blade, there isn’t much to do. Forge in a gentle taper and put in any curve you might want. For a hidden-tang blade, taper both the width and thickness to fit inside the handle you will use.

Step 4) Normalize: This is a gentle heating and cooling of the steel to help “straighten out” the molecular structure after forging. With the steel at a “black heat,” or not glowing, gently and slowly heat the blade until it starts to glow. You will start to see those shadows mentioned earlier. As the temperature continues to rise, the shadows will disappear. Just after the shadows vanish, pull the blade from the forge and allow it to cool in still air until it turns black. I usually do this twice. For many high-alloy steels you will want to skip this step. Follow the manufacturer’s recommendations.

Step 5) Annealing: This softens the steel in preparation for cutting, drilling, grinding and future heat treating. I usually do what is called a spheroidize anneal. The spheroidize anneal leaves the cementite (iron carbide) in little spheres as opposed to the “hot dog” shapes of the full anneal. The spheroidized steel cuts and machines easier, with less residual stress. You need a kiln for this. If you don’t have a kiln, stick with the water-hardening steels and do a full anneal.



The forging is finished. After annealing
it will be ready for finish grinding. (Nathan
Zowada photo)

A full anneal is pretty simple. Heat the steel until the shadows disappear, as in Step 4, then bury the blade in dry lime, vermiculite or wood ashes. It won’t be a great anneal but it will get the job done.
Once the blade is cooled after annealing, you will be ready to do the finish grinding.
Of course, to each his own, but I have always thought it more fun to hammer on a piece of steel until it looks like a knife instead of grinding away everything that doesn’t look like one!



The author forges the bevel using glancing
blows near the anvil’s edge. (Nathan Zowada
photo)

For more information contact Tim Zowada, Dept. BL12, 4509 E. Bear River Rd., Boyne Falls, MI 49713 231.348.5416 tim@tzknives.com, www.tzknives.com.

[1] Tool Steel Simplified, Fourth Edition, Palmer, Luerssen and Pendleton, Carpenter Technology Corporation, ISBN 0-8019-6747-3.