Sword-hilted Broken-back Seax

Wherein Ben explains some of the processes he uses.

This instructable is from a tutorial on my website:
www.seekyee.com/Bladesmithing/the%20process/tutorials/seaxtutorial1/seaxtutorial1.htm

For more information about me and my work and links to my blog please visit my website:
www.seekyee.com/Bladesmithing/index/index.htm

Step 1 The Design

Once I have decided to make a piece I begin by making several rough sketches. If I am
working with a customer then I use the feedback from these sketches to refine the design.
The Final sketches for this project include the profile view and a full-scale rendering of the hilt

Comments

[Grimmy Grim]

Simply WOW!

What talent and ability!

[Ray from RI]

As Mr. Burns would say EX.. celletn!!!

You do nice work!!! And your Celtic/Norse art work is excellent as well!!!
I have been looking at collecting books on Celtic, Early Germanic, Anglo-Saxon and Viking Art. art history, mythology for over 20 years and have been creating my own interpretation of a Celtic/Viking style of art for 15 years.

I would say both your artwork and metalwork are outstanding!!! Very Cool!

[black hole]

How thick is the blade after you're done?

[curvy77]

im glad to see another intrested in norse style. iv looked at this before and was confused on the design. of course that didnt stop me from borrowing it. where do you get your ideas for the handle?

[deobomb]

good frigin god this is a proses GOOD JOB MAN!!

[skimmo]

i dont have access to a forge atm, you reckon that I could cut a piece of plate still into the same shape, I know its not the same but itll be closse

[ben potter]

you can it is called stock removal.

[skimmo]

i dont get it

[ben potter]

There are two ways of crafting blades, forging(forming the metal into shape) and stock removal (starting with an over-sized piece of STOCK and REMOVING the excess until you have the blade). both are equally legitimate and with the right techniques make exelent blades. Good luck.

[skimmo]

i get it now! thanks

[ninja of suburbia]

Unfortunately, with a stock removal process, you do not get the infusion of carbon into the blade that you do with a forging process, but this can be accounted for by using very high quality steel.

[Ferrite]

That is actually untrue. There are very specific temperatures and conditions at which carbon is absorbed into the blade and most of the time when a piece of metal is in the fire it is actually decarburising not gaining carbon.

[ninja of suburbia]

I looked at your profile, and one of your interests is blacksmithing. out of curiosity, are you a blacksmith, or do you just like blacksmithing? Either way, the loss of carbon in the forging process is slow, but the infusion of it at those temperatures you mentioned is very rapid. Put simply, it is like filling a leaky tank with a fire hose. this process is what allowed ancient swordsmiths to create steel weapons when forging from Iron ingots. Japanese swordsmiths still use this method to create rare and beautiful swords. their materials are mainly comprised of iron-bearing sand and low-grade iron. these materials are made into steel by the infusion of carbon during the smelting and forging processes. granted, most of the carbon infusion occurs during smelting, when the metal is at a liquid form, and thus far more susceptible to carbon infusion, but a substantial amount of infusion occurs during the forging process itself. It is preferable to begin with a high-carbon blank or stock piece, but the reasoning is that it simply is easier to begin with a high grade piece than it is to bring the carbon content of a lower grade piece up.

[Ferrite]

I am a blacksmith. From what I have read, mainly in the Wayne Goddard Art of Knife making book, what you say is untrue. If you have a source that shows otherwise I would be happy to read it but the conditions that you use to forge the blade are not enough to significantly add carbon. What you say about the carbon infusion during the smelting is true, about the forging I would say not.

[ninja of suburbia]

no, of course it doesn't significantly add carbon, at least, not enough to raise the carbon content very far, which is what I've been saying the whole time. the infusion of carbon at those few temperatures isn't enough to, say, raise the grade of the steel, but it is more than enough to maintain that grade. So, it seems we've been arguing two sides of the same point, and that is, that smelting is the only practical way to significantly raise the grade of the metal, but that, by using certain forging techniques, it is possible to maintain the carbon content of the piece you are working.

[brandon_a_boyer]

It doesn't even have to be very high quality, anything above 1040 would be more than adequate.

[skimmo]

at the moment i am working on a stock removal saw using a chainsaw bar its coming out awesome

[brandon_a_boyer]

Some of your Information is incorrect.

Tempering converts some of the martensite back into iron and Iron carbide.

Also, why three heat treatment cycles? A single two hour cycle should be more than sufficient for this purpose.

[ben potter]

The tempering has to do with gain structure rather then actual composition. Three cycles are necessary to convert as much of the steel to martensite as possible, for a full HT it takes three cycles over a tree day period to insure that all of the steel that is going to convert has and that it has all been tempered. The transformation to martensite happens as the steel cools and more of the steel will convert if you heat it and cool it additional times (Three times being the best as additional cycles do not convert much more steel and have other less desirable effects). There is a fair bit more to it but it would take too long to type it all out.

[brandon_a_boyer]

Three cycles are not necessary for total conversion of martensite.

there are several different structures that occur in an iron and carbon solution

ferrite (iron)
Iron carbide
Martensite
Pearlite
cementite
austenite

the ones critical to our discussion are austenite and martensite. Generally speaking all martensite is, is an unstable form of of austenite that occurs at elevated temperatures. Rapid quenching freezes the molecules in place and causes the steel to remain in an austenitenitic structure. All you are doing by tempering is allowing some of the steel to return to it's austenitic state.

I'm sorry but whoever gave you your heat treat information was incorrect.

[ninja of suburbia]

Actually, Ben is right. To simplify what happens, when high temperature steel is quenched, it locks the grains into a high tension structure. This structure is very hard, but is very brittle. The tempering allows some of the crystalline structure to soften, making the blade softer, but far more malleable. Heat treating allows the steel to not only convert to a Martensitic structure, but makes it more resistant to wear and heat, as this structure is very solid and hard to break down. Austenite steel is only formed when the metal is heated to high temperatures, and loses its magnetic properties during forging. This is very short lived, reverting back to the high tension crystalline pattern when quenched. Therefore, Austenite is irrelevant except as a time gauge to use when forging, as this property of lost magnetism indicates the optimal time to forge, as well as the optimal time to normalize, a process by which one lines up the blade with a compass needle, forcing the magnetic particles within the steel to align with the Earth's magnetic field, forming lines down the blade, rendering the blade stronger, and not unlike a very weak form of pattern welded steel.

[brandon_a_boyer]

You're only partially correct.

If you quench carbon steel while it's at high temperature (900 C +) it forms the non-equilibrium phase of martensite. Which is hard brittle, and unstable. What tempering does is it returns some of this marstensite into austenite, then into it's other equilibrium phases. Resulting in a more durable blade.

Ben said that tempering turns the steel into martensite, which is just flat out wrong. The only time martensite is formed is during the initial heat, and quench.

Sorry, but your statement about holding the blade in alignment with magnetic north is just ridiculous. It does nothing to make the blade stronger. It's an old smith's tale. Proper heat treatment goes much further.

[ninja of suburbia]

Au contraire. The magnetic alignment may not affect the overall strength of the blade very much, but it does help to prevent chips in the blade, which is very desirable, for obvious reasons. We are in agreement about the tempering conversion, because tempering merely loosens the crystalline structure, giving a blade ductility.

[brandon_a_boyer]

It doesn't "loosen" the crystalline structure, it changes it so that the number of slip planes increases, making the material more ductile

Don't pretend that the magnetic alignment does anything for the strength of the steel. This does absolutely nothing. The closest thing to what you are talking about is a cooling technique that they use for turbine parts, and all that achieves is an increase in high temperature strength.

[ninja of suburbia]

I don't know what you're talking about with turbine parts, all I know is what I have seen in my own experience, and it has been my experience that aligned blades chip far less often than non-aligned blades.

[brandon_a_boyer]

And that's probably true, but not because of the earth's magnetic forces. All that is happening is you are allowing the steel to air cool a bit, which causes some of the martensite to change into softer states, making the blade less brittle (AKA Normalizing.

[ninja of suburbia]

Regardless, that's the way I learned from my master, and that is how I will continue to do it.

[brandon_a_boyer]

And that's fine. It's perfectly normal for someone to hold on to their beliefs. Although I would recommend either taking a materials science course or picking up a book specifically on materials science. Also the ASTM heat treater's handbook is a great thing to have.

[_Scratch_]

Do you have a full forge to heat your steel in? Or do you use a sort of smaller home made one?

[ben potter]

I use a smaller forge for forgeing and a larger one for the heat treating.

[zanshook]

great work!

who else wants to come with me to kill justin beiber with this!?!?!

[The Metal One]

i do! i just made a dirk with this process and would like something soft and spineless to test it out on, lol.

[The Metal One]

great instructions! i recently crafted a dagger using the same process, minus any heat treatment. i will post some metalworking and woodworking projects soon,so check em out when i post them.

[_Scratch_]

Amazing job. I can only dream of making something like that.

[evilgenius 398]

that is pretty amazing. you are good man

[nuurgh]

This sir is an AWESOME build.
I regret being iterested in so many things I would try even blacksmithing...

[Mjollnir]

Looks epic, thanks.

[henster22]

could you have any more steps?/?

[the_burrito_master]

I know you don't make katana's but here's my summer project that your instructable has inspired me to do.

I'm probably going to have top re-craft the habaki (blade collar) and the the tsuba (handle guard)

I still haven't heat treated I'm still polishing it.

This is my second ever sword btw.

[ben potter]

Nice looking sword.