Medieval adventures

Pattern Welded Seax

Knifemaking is a lot of fun. It can be done with a piece of flat steel and a grinder. That’s not much of a challenge though. In Anglo-Saxon times knives were made on a forge and called a seax. A distinctive feature with many of these knives is a wavy pattern that appears in the metal. This is done by welding various pieces of iron/steel together with different carbon contents. This technique is called pattern welding. It is also commonly referred to as Damascus, but that is really pattern-welded steel that comes from the Damascus region.

The first step is to make a billet. This is basically a set of metal plates that will be welded together. I used some band-saw blades, circular saw blades and a file. The idea here is to pick metals with different carbon contents.
I originally welded the billet to a rod, thinking that would work. Later on, I discovered riveting a billet loosely together with common nails worked well. There was no trace of the nail when the knife was finished. It is very important that the metal be ground clean of rust and paint.
I got the forge going and headed up the billet so that the Borax would melt onto it.
The Borax acts as a flux, that prevents the metal from oxidizing.

After the billet is welded, square up the sides and elongate it. You can then cut it almost all the way through with a chisel/cutter, and fold it in half and weld again. Make sure you brush/grind the surface clean before doing the next weld. Each time you fold you double the pattern. I usually do two or three welds and end up with 12 to 24 folds based on the doubling rule.

Elongate the billet and hammer it into a bar of about 1/2-inch thickness. You can then heat up the bar and twist it in a vice. This makes a unique pattern. Hammer it back into a bar and then forge the knife.

The trick to forging a knife is to keep the tang (handle) in the centre of the plate. It’s tricky! It is also hard to keep the blade from curving. This is because the blade edge is thin while the back remains thick. Seaxes are single edged knives. I apologize for a lack of pictures explaining this and will update this soon.

Hopefully, you will end up with a seax blade that is pretty close to the finished product. At this point heat it up to yellow and let it slowly air cool. Make sure the blade evenly cools. What you are trying to do is to remove all hardness from the metal so you can grind and polish it. I use a variety of grinders to do this job. Flap disks are great.

At this point, you may be asking- where is the pattern? Have no fear, you won’t see that until the very end of the project. If you just can’t wait, put the knife in pickling vinegar for awhile. The pattern will begin to appear. Hot vinegar will make it show up faster.

You are now ready to make the blade tough and hard. First you harden the blade by bringing it up to yellow. Make sure the entire blade is uniformly the same colour. Be careful not to burn the blade. Remember the knife edge will heat up much faster than the back. You might want to put the blade back-side down to avoid burning the thin edge.
Take it out and make sure the colour is uniform. You can take a few seconds and turn the blade to make the heat even. Now you can quench it in water or oil. I don’t think it makes much difference which you use, but water cools faster and is not as messy. The picture below is oil, but I won’t bother with that again.
Now you will have an extremely hard, and very brittle blade. If you smack it with a hammer at this point it could easily break in half.
Don’t bother trying to polish the knife at this point. It will be way too hard. All the shaping needed to be done previous to hardening.
Now you are going to temper the blade. This will make it hard and tough and should hold an edge. To do that you need to bake it for several hours at a constant temperature. You will notice the blade changes colour as it tempers. Colours vary from yellow to blue. Yellow is what we wanted, so we baked it at 350F and also cooked a roast. 400-450F for four hours is a good temperature.