Hello all.

I'm planning on building a a nice big seax somewhere between 5-10mm thick and with about a 24 inch blade. I'm working out the dynamics of the profile, and using a novel curved handle to change from cleave/chopping to thrust/shearing depending on your grip.

Now, the closest I've come to making knives is hammering a nail in a homemade forge, and using a belt sander on a file (unfinished).

I make a lot of lovely wooden training knives, and I find that valid enough to test size/shape with, but this is a serious investment project.

I want the midddle of a san-mai structure to be made of something fancy and reliable like CPM-3V, which I hear should be good for big choppers given it's high toughness and wear resistance at a given hardness. Anyone know enough about the stuff to say if it could be a 'good choice'? I leave that intentionally vague, as I can work wonders with a $7 440b machete.

And then the plan expands into making the "bread" of the San-mai sandwich from a lovely pattern-welded set of sheets, much like the beautiful 'charlemagne' Seax we all love so much here.

The knife is intended as a present to my younger brother, who is a pain, but had done his research on European history and inspired me to do the same.

So the question is: would 3v be 'ideal' for such a piece, or is there a big downside to this particular steel? He isn't very...um...'gently' on his (or anyone else's) tools, you see.

Any input would be really helpful.
Thanks;
- Andrew Dodd

It depends partly on what your outer material is constructed from (the pattern welded 'bread') But I would say for a sword length blade your best bet is gonna be a simple steel that can yeild good results from simple heat treating like 1075, W1, or if you want something with a little more alloy 5160. basicaly there is no magic formula, and if there is one it is to keep it simple, especially when your talking about long blades. the simple steel is gonna be more rewarding and end up giving you a better blade in the end. I would also advise that you try forging a practice run for your project in mono steel before you try the san mai construction, the heat treating can be quite challenging enough without the added complication of pattern welding.
I've been making swords for about 11 years and basically what I've learned about steel is that 'fancy' isn't reliable. simple = reliable
that's my $0.2

I'd plan on doing some experiments first... Try a couple san-mai knives and forge out a monosteel trial piece. It's easy to get discouraged when something goes wrong if the investment is a big one... :)

My two cents are CPM-30V will not forge weld. Hack.. I think you can´t even forge it! Some might forge it, but with very good temp control and good skill not to stress it too much. If a chopper is in scene I would use the good old 5160. It´s been winning cutting competitions for years and almost all JS use for the ABS test. It will perform well for you.

Great advice there: fancy isn´t always best. Nice shot Jake.

I'd plan on doing some experiments first... Try a couple san-mai knives and forge out a monosteel trial piece. It's easy to get discouraged when something goes wrong if the investment is a big one... :)

I'm planning on testing the design in monosteel, to be certain of the validity of the final investment. I found a giant spring from a dumptruck's suspension in the snow. I figure that should be enough steel, good or not.

I hadn't thought about the heat treat differential using the 'special' steels vs. the 'other' pattern-welded sides. I'll have to think about that.

Thank you all for justfying my process questions.

My two cents are CPM-30V will not forge weld. Hack.. I think you can´t even forge it! Some might forge it, but with very good temp control and good skill not to stress it too much. If a chopper is in scene I would use the good old 5160. It´s been winning cutting competitions for years and almost all JS use for the ABS test. It will perform well for you.

Great advice there: fancy isn´t always best. Nice shot Jake.

FANCY ISN"T ALWAYS BEST.
Oh, that was a life lesson I got quite early on, and thank you for iterating it.

If you think 5160 works well, then I think I'll try something similar first.
Maybe that or A2. All the knives I have now are all A2, and they're great. So great, in fact, that I don't often use them, as they cost almost $400 each.
So I have no real experience, or even reason for comparison.
I was just afraid that if I used something cheap it might just break.
Then again, it'll be thick and fat and convexed, so it should be strong by design, right?

I chose CPM-3V to ask about since it appeared to have rediculously high wear resistance and toughness at relatively high hardness. Never worked with any of those steels. My thoughts turned briefly to stainless, but I shut that down early.

5160 series steel is good bet. Tony and Rocky Lemon over at Oso Forge use it for mono steel swords. I will be using it on my first sword attempt. And last, I am told it is the steal of choice for those taking the ABS Journeyman Test, because of it's thermal properties.

These are great answers. I still have a hard time getting over that I"m getting personal replies from such people as J. Arthur Loose and Jake Powning.

[If knifemaking was comics, they'd be like 'batman' and 'spiderman' to me ;-) ]

I'm thinking of setting up a little forge across the street in High Park (500 acre urban forest space), and try forging out the lump of metal I found. I will of course heed your common sense advice of trying some simple monosteel practice pieces to find out sweet spot, balance point, wieldability under whatever circumstance and functional attributes, then vary the design based on my findings, amking it longer/shorter, thcker/thinner, alter the angle between handle and blade, etc.

I'm even trying to base the ratio of the parts on the golden mean, to see what happens.
My first experimental versions are all made of wood, but that only gets you so far.

I'll look up oso forge for fun.

Thanks again everyone for your replies and thoughts.
- Andrew Dodd

These are great answers. I still have a hard time getting over that I"m getting personal replies from such people as J. Arthur Loose and Jake Powning.

[If knifemaking was comics, they'd be like 'batman' and 'spiderman' to me ;-)


Hear that, Jake? Dibs on Spiderman! I know Batman is cooler, but I have a soft spot for smartasses & redheaded chicks. ;)


I'm even trying to base the ratio of the parts on the golden mean, to see what happens.
My first experimental versions are all made of wood, but that only gets you so far.


That should prove interesting. Even the wooden ones.

Do post!

Oh good! I was worried we where gonna have to duke it out for the Batman spot. i'm with ya on the redheaded chicks, but I'm more of the dark night tipe than the bouncing scientist, I'd just as soon stay cleer of the whole radioactive thing anyway.
I was pretty sure when i was a kid that I was gonna be batman when I grew up, I guess this is as close as I'm gonna get :photo:
he he
I've got quite a collection of Detective Comics getting moldy in the barn.