Damascus coreless blades -- how are they as cutters?

[gwhphoto]

Something caught my eye recently as I was looking around at blades.

Several makers offer what they call "coreless" damascus knives. This is the forge welding of two different steels together to make the damascus pattern layered steel, and then shaping and grinding that steel to become the actual blade instead of using it as cladding layered over a different steel core. This is done by several makers including Shun at the more "standard" end, up to Ryusen (both of them combine two different stainless, usually VG 2 and VG10) and, at the highest end, Hashimoto, who combines white and blue carbon steels.

What purpose does this type of construction serve? Does it increase the cutting prowess of the blade compared to, say, my Takana x Kyuzo Blue 1? One description said that the steels wear microscopically differently so that the edge is "toothier". Does this also happen when you sharpen?
They are certainly beautiful, but is there any advantage to them?

Has anyone had experience actually using these types of knives?

Thanks

 

[Barmoley]

@Larrin is doing a huge damascus (forge welding) steel study which he will reveal results for at blade show and hopefully later on knifesteelnerds.com. We will know more after that. In theory one would think that combining 2 or more steels will create a material with performance somewhere in between of the steels used. So if one steel is tougher and the other more wear resistant the resulting material is tougher than the least tough steel and more wear resistant than the least wear resistant steel. On the other hand it is not as tough or as wear resistant as the individual steels used. The other question is, does the number of layers make a difference, it seems like it should to some degree.

Here's an older article on the subject Five Myths About Damascus Steel - Knife Steel Nerds

 

[MSicardCutlery]

Knifesteelnerds already covered this to some extent. Essentially the properties of the individual steels are averaged out. See myth #5: Five Myths About Damascus Steel - Knife Steel Nerds

 

[Delat]

I’d expect in practice there wouldn’t really be a noticeable difference, and that coreless damascus is really just for show. In theory you could mix and match for different properties as @Barmoley discusses, but in practice remember that you’re subjecting the various metals to the same heat treat. So you can’t have two metals that require significantly different heat treat; I suspect that’s why you see a few common combinations used for coreless, because they’ve been proven to work well together when treated the same.

 

[MSicardCutlery]

Usually they're selected for contrasting etch, since damascus is basically just for aesthetics.

 

[blokey]

Basically what other people said above. Pattern welding from 2 or more steel is probably as old as steel making itself, even stainless “cordeless” has been made by makers like Devin Thomas since 80s (or 90s), it’s just the commercial manufacturers has caught on and advertise it as some magical “true”Damascus.

 

[gwhphoto]

Thanks so much everyone! Really takes a lot of the mystery out of it.

I posted the same question on Reddit and someone sent me link to the Takefu specialty steel site. It seems that the "coreless" material comes pre-made from them (presumably with some input from the blacksmith about how many layers, etc). I also noticed that they produce "rainbow" cladding seen on a lot of knives (including one of my own!).

In fact, it explains something that baffled me a few months ago. I saw a post of a knife made by a smith called Jaime Nerkowski. It was a beautiful gyuto with dark carbon core steel and a stainless clading with curvy horizontal copper and bronze stripes--more like tiger stripes than the circles and swirls of most rainbow damascus. Then, a month later, I saw a knife made by a smith called DiKristo--the "Aetna" knife. It was absolutely, positively, the same. Looked completely identical. So, did Takefu have a special on this particular billet and a few people bought it and made knives? No disrespect to the smiths, but it is a question that has been in the back of my mind.

So, then, what does the blacksmith bring to the process besides shaping and grinding? I will assume they tell Takefu (or an equivalent) what steel they want in terms of # of layers, types of steel, etc. They then get the pre-made steel which has already been manufactured, rolled and heat treated. Where does the forging at the blacksmith's shop come in and what does it add?

No sarcasm intended, I am genuinely interested. These posts, though, seem to be removing a lot of the mystique behind the knives as some sort of special wizardry by a jedi working alone at his forge in a remote area . . .

 

[MSicardCutlery]

Where does the forging at the blacksmith's shop come in and what does it add?

No sarcasm intended, I am genuinely interested. These posts, though, seem to be removing a lot of the mystique behind the knives as some sort of special wizardry by a jedi working alone at his forge in a remote area . . .

Sometimes taper to the billet, so that there's uniformity to the exposed portion of core as the knife is ground with a taper. Sometimes...nothing. Sometimes distortion of the layers to make the pattern more active.

 

[Delat]

I have a cumai from Newham that I suspect is from Takefu. Sometimes the maker will say that it’s from Takefu (I forget if Newham did or not), other times if you see the exact same thing from different makers then that’s a pretty big clue. I assume the blocks are not heat-treated; the maker does quite a bit - they still have to turn that block of steel into a functional knife.

Some makers have been custom making their own coreless, and stainless-clad damascus-core (Black Lotus was the first I personally saw with that combo), which is a pretty cool look and I’d love to get a stainless-clad damascus core one day simply because I like the way they look. I have a coreless Damascus custom in the works with Henry Hyde that I’m looking forward to as well.

This one from Neil Ayling I’d totally jump on if I didn’t already have a custom in the works. Damascus core, copper shim, stainless cladding.

 

[blokey]

Thanks so much everyone! Really takes a lot of the mystery out of it.

I posted the same question on Reddit and someone sent me link to the Takefu specialty steel site. It seems that the "coreless" material comes pre-made from them (presumably with some input from the blacksmith about how many layers, etc). I also noticed that they produce "rainbow" cladding seen on a lot of knives (including one of my own!).

In fact, it explains something that baffled me a few months ago. I saw a post of a knife made by a smith called Jaime Nerkowski. It was a beautiful gyuto with dark carbon core steel and a stainless clading with curvy horizontal copper and bronze stripes--more like tiger stripes than the circles and swirls of most rainbow damascus. Then, a month later, I saw a knife made by a smith called DiKristo--the "Aetna" knife. It was absolutely, positively, the same. Looked completely identical. So, did Takefu have a special on this particular billet and a few people bought it and made knives? No disrespect to the smiths, but it is a question that has been in the back of my mind.

So, then, what does the blacksmith bring to the process besides shaping and grinding? I will assume they tell Takefu (or an equivalent) what steel they want in terms of # of layers, types of steel, etc. They then get the pre-made steel which has already been manufactured, rolled and heat treated. Where does the forging at the blacksmith's shop come in and what does it add?

No sarcasm intended, I am genuinely interested. These posts, though, seem to be removing a lot of the mystique behind the knives as some sort of special wizardry by a jedi working alone at his forge in a remote area . . .

Copper clad, Mokume exist before Takefu, there’s even a thread right now. Tho most do use Takefu billet. I don’t think Takefu sell heat treated billet, that’s up to the maker.
https://www.kitchenknifeforums.com/threads/amateurs-guide-to-making-mokume-gane.65296/#post-1001002

 

[Matt Jacobs]

It's going to come down to the steels used. I have had great luck with Damascus blades out of 1084/15n20, to me it holds a toothy edge longer than just 1084 for example. From a performance stand point I would take a good core steel like Apex Ultra / Cru-ForgeV etc with cladding over a Damascus core steel but if I had one from better steels than 1084/15n20 I suspect I would love it. I am not a huge fan of the term "coreless Damascus" To me it is either a Damascus cutting surface or Damascus clad over a core steel.

 

[gwhphoto]

Your terminology seems exactly correct. I was just using what the advertisements use.

 

[Matt Jacobs]

Your terminology seems exactly correct. I was just using what the advertisements use.

Agreed, I have seen it advertised before I just never understood why. Maybe so many Japanese knives are Damascus clad so they wanted a different term. Or they wanted to differentiate from Pakistan Damascus

 

[Eloh]

Also to keep in mind, there's always a 'good' chance to degrade the steel qualities during forgewelding, when done not perfectly.
Thats also the case for san mai though, wixh is a bit easoer to do correctly though

 

[Joyner]

Hello, I do not know much about the history of Damascus blades, but just for discussion, here is a knife that I believe is vintage with a "100% Damascus" blade. It appears to have some age to it and seems pretty well made and was a user. I purchased it from a seller in India - I though it was a decent knife and that it was interesting. I have no idea what kind of steel and I have not tried to sharpen it to see if it holds an edge.

 

[esoo]

Fredrik Spare makes them currently. I sold the one I got as the dimensions weren't to my preference, but they are quite nice

 

[jedy617]

@Larrin is doing a huge damascus (forge welding) steel study which he will reveal results for at blade show and hopefully later on knifesteelnerds.com. We will know more after that. In theory one would think that combining 2 or more steels will create a material with performance somewhere in between of the steels used. So if one steel is tougher and the other more wear resistant the resulting material is tougher than the least tough steel and more wear resistant than the least wear resistant steel. On the other hand it is not as tough or as wear resistant as the individual steels used. The other question is, does the number of layers make a difference, it seems like it should to some degree.

Here's an older article on the subject Five Myths About Damascus Steel - Knife Steel Nerds

I was going to post that as well. Will be interesting to see. In terms of usage, I find my damasteel knives to be pretty similar to straight RWL34/CPM154. I'd expect in testing it will be 25% ish within the range of performance of straight RWL.

 

[Olsen]

I have some "mono-mascus... One from Catcheside, Smedja Aspen, Halcyon Forge and Green Stag Forge.... they all cut beautifully... It has all to to with the steel combination used. Is it necessary???... no. Is it cool???... Yes

 

[kman94]

Thanks so much everyone! Really takes a lot of the mystery out of it.

I posted the same question on Reddit and someone sent me link to the Takefu specialty steel site. It seems that the "coreless" material comes pre-made from them (presumably with some input from the blacksmith about how many layers, etc). I also noticed that they produce "rainbow" cladding seen on a lot of knives (including one of my own!).

In fact, it explains something that baffled me a few months ago. I saw a post of a knife made by a smith called Jaime Nerkowski. It was a beautiful gyuto with dark carbon core steel and a stainless clading with curvy horizontal copper and bronze stripes--more like tiger stripes than the circles and swirls of most rainbow damascus. Then, a month later, I saw a knife made by a smith called DiKristo--the "Aetna" knife. It was absolutely, positively, the same. Looked completely identical. So, did Takefu have a special on this particular billet and a few people bought it and made knives? No disrespect to the smiths, but it is a question that has been in the back of my mind.

So, then, what does the blacksmith bring to the process besides shaping and grinding? I will assume they tell Takefu (or an equivalent) what steel they want in terms of # of layers, types of steel, etc. They then get the pre-made steel which has already been manufactured, rolled and heat treated. Where does the forging at the blacksmith's shop come in and what does it add?

No sarcasm intended, I am genuinely interested. These posts, though, seem to be removing a lot of the mystique behind the knives as some sort of special wizardry by a jedi working alone at his forge in a remote area . . .

Yes you can buy the pre-made billet of damascus from Takefu as well as san mai billets, cu-mai etc. My personal opinion is if you start knife making, you quickly realize it isn't the easiest to forge weld your own billets, so buying pre-made, consistent billets is a nice option. Also, if you're a stock removal knife maker, it's pretty much the only way to get them. There are knife makers that sell their damascus billets as well like Salem Straub or companies like Baker Tool and Forge.

I think to say that the bladesmith *just* brings shaping and grinding to the picture is fairly demeaning to bladesmiths. I would argue outside of a good heat treat (which is pretty easy to do with a heat treat oven), the grind and geometry is the hardest and most important part of knife making.

 

[Larrin]

I got the presentation done for Friday. Might be too action packed for an hour.

 

[jedy617]

I got the presentation done for Friday. Might be too action packed for an hour.

Have fun at blade, wish I could be there. Is it gonna be recorded for YouTube?

 

[user 51158]

I made couple of knives with takefu steel and have a lot pre made for future knives.
The quality of there steel i really like. I myself dont forge patyern welded steel and i do mostly stockremoval.
However with the steel from takefu you have to forge texture in to the steel to give movement in the layers.
If you dont do that and just do “stockremoval” without hammering texture you will get straight lines.