San Mai Question

[Chris623]

I'm not to the point of even trying San Mai, but I was just sitting here considering what I'd do...........if I could.

I'd like to make a heavy chopper for my brother. I want it tough as nails, but also want it to have some flair. My first thought was Damascus, but Walter Sorrell told me the cutting edge would be sharper and hold it's edge longer if it were another material. So I'm thinking San Mai with a 1095 core and Damascus outer surface. I'd make the Damascus with a low count twist (because I like that look) and would leave some forging marks up toward the spine. From the heavy chopper/Camp knifes I've seen, they typically have a single/long bevel. Would that defeat my purpose of putting the Damascus on the outer surface?

 

[Doug Lester]

First, I'm the last person to ask about leaving "decorative" forging marks behind, but to each his own. If I were going to make a san mai blade I would forge weld a flat billet making certain that the core material remains centered. I would then form the outline of the blade without forging in any of the bevels. The bevels I would handle by stock removal and care will have to be take to keep the core centered. Whatever steels you use, make sure that they are compatible or the blade might tear itself apart in the quench.

Doug

 

[Chris623]

Thanks for the input, Doug. I personally don't care for forge marks remaining on blades.............but my brother seems to like it and the knife would be made to make him happy, though I'm tempted to try and talk him out of it. I totally agree not to forge the bevel on this blade because I definitely want the core to stay centered. Am I correct in the choice of 1095 for the core of the chopper? What steels would you recommend I make the Damascus out of?

 

[KenH]

I want it tough as nails

If my main concern was "tough as nails" then neither San Mai nor Damascus would be my first choice. I'd be thinking of a good mono steel..... for high carbon perhaps 5160?

 

[Chris623]

The core out of 5160? I'd planned on 1095.........is that a problem? The San Mai (with "whatever" material) would just be for decoration.

 

[EdCaffreyMS]

The core out of 5160?

My advice is don't. Simply put, 5160 does not play well with others. It's one of the best steels for hard use....when use in a mono steel format, but forge welding it is risky as best.

There's a lot of IFs when you're considering a San-Mai, and wanting "tough as nails". IF you choose the correct materials....... IF your understanding and capabilities of forge welding are solid....... IF you technique is sound..... and within each one of those resides any number of additional IFs.

There's a good reason you don't see any ABS members testing for Mastersmith with a San-Mai blade....... it's not because it can't be done, but the risk of failing is high, and the skill level required to produce a San-Mai blade that will succeed is equally high.

Personally, if someone asked me for a knife, and used the words "San-Mai", and "tough as nails" in the same sentence, I'd simply refuse to build it for them. Why? Because I know and understand the limitations of what I produce. Were I to say yes..... I'd likely later be trying to explain to a client when his San-Mai blade did not hold up when he did something totally stupid with it...like attacking a steel drum, stabbing it through a car hood, chopping a concrete block, or some other stupidity.

 

[Chris623]

Thanks, Ed. As usual, your response is more than helpful. So would you recommend I stick with 1095 for the core and just used a Hamone for decoration? Or would there be a better steel to use for this Camp/Chopper knife?

 

[KenH]

Ed posted while I was writing this - and I agree with Ed 100% on the idea of San Mai. That's why I wrote " I'd be thinking of a good mono steel..... for high carbon perhaps 5160?" To paraphrase Ed "5160 is one of the best steels for hard use" - NOTE, this is solid mono steel blade. NOT San Mai nor Damascus. Ed is one of the gurus on Damascus so you can take his word to the bank.

Oh, if you're just wanting to make some San Mai then 1095 should make a good core. That's what I've been using for the few billets I've made. Here's the contrast I get with 1095 core and 416SS cladding:

 

[Daniel Macina]

Hopefully this isn’t considered hijacking the thread but I had a quick question On San Mai and hate to start a thread for one question.

Just how much forging can you get away with once you have the billet of San mai made? Is it the type of thing you pretty much have to make the billet and grind the knife or can you forge pretty close to shape if you’re careful?

 

[EdCaffreyMS]

Daniel: That amount of forging the material(s) will allow is based on the materials you choose. You've likely heard me say "there are always give-n-takes" in everything we do..... You can do a lot of manipulation when the materials are very "compatible" (such as two similar carbon steels) What you give up is the eye appeal, as it will not be as strong as with a carbon/stainless mix. With a carbon stainless mix, it's pretty much dry weld the three components (1 core and 2 exterior layers) and then grind from there.....trying to manipulate a carbon/stainless mix is often a disaster.....although Karl Anderson does it.....and is VERY good at it. What you give up with this combo is that ability to manipulate.

So it's always a tightrope we walk.....lean too far in one direction and we fall off. Leav too far in the other direction and we fall off. Making wise choices in materials and understanding the limitations (and the strengths) of those materials is often the difference between success and failure...... and OF COURSE..... when it comes to forge welding ANYTHING......there are going to be failures....learn from them, and in the not too distant future it'll be old hat for ya.

 

[EdCaffreyMS]

So would you recommend I stick with 1095 for the core and just used a Hamone for decoration? Or would there be a better steel to use for this Camp/Chopper knife?

Sounds like your mind is made up that it will be San-Mai? If so, then here's my recommendation. Make your exterior pieces for 1095/15N20 damascus. Then, use 1095 for the core of the blade. Leave yourself some room when building your San-Mai billet. Make you 1095 core 1/8-3/16" thick, and the exterior damascus pieces 1/4 thick. With these materials you can either dry weld, by running and air tight MIG beade all the way around the edge...... or it could be flux welded too. Don't worry about exposing the core during forging! That's why things are thick.....you'll expose it during grinding, when grinding the bevels.

Keeping the core centered is the most problematic things with San-Mai. Get the core off center, and nothing else is gona work right. Once you get a good forge weld on it, go through your normalizing, thermal cycling, and annealing.....then grind from there. Because of the 1/4" exterior, you'll have to grind a significant amount off, but you can always keep an old/no good jub of ferric close, and dip the billet every now/then to see where the core is....and center it by grinding side to side based on what your eyes are telling you when you dip it, and look.

OK....if I'm wrong there, and your open to a mono steel blade, my choice would be and edge quenched 5160 blade...... you'll get the appearance of a hamon, with the toughness you're looking for.

 

[Chris623]

Thanks for your comments, Ed. Helpful, as always.

It sounds as if I'm just trying to make problems for myself. Guess San Mai is way, way, way beyond my skill set. I just thought it would be easier than that. I'm definitely open to a mono steel blade...............but I'm looking for something besides a plain look. (which is why I was thinking about the San Mai in the first place) Maybe I'll just leave some tiny forging marks on a small strip up toward the spine on a mono steel and see if that gives the blade any character. That's what my brother would like, anyway.

 

[Daniel Macina]

Daniel: That amount of forging the material(s) will allow is based on the materials you choose. You've likely heard me say "there are always give-n-takes" in everything we do..... You can do a lot of manipulation when the materials are very "compatible" (such as two similar carbon steels) What you give up is the eye appeal, as it will not be as strong as with a carbon/stainless mix. With a carbon stainless mix, it's pretty much dry weld the three components (1 core and 2 exterior layers) and then grind from there.....trying to manipulate a carbon/stainless mix is often a disaster.....although Karl Anderson does it.....and is VERY good at it. What you give up with this combo is that ability to manipulate.

So it's always a tightrope we walk.....lean too far in one direction and we fall off. Leav too far in the other direction and we fall off. Making wise choices in materials and understanding the limitations (and the strengths) of those materials is often the difference between success and failure...... and OF COURSE..... when it comes to forge welding ANYTHING......there are going to be failures....learn from them, and in the not too distant future it'll be old hat for ya.

Thank you very much sir! Hope you are well!