Damascus - What exactly is it?

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bonestter

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Just when I thought I had 'got it' looks like I know nuffin when it comes to Damascus knives

The way I think it goes

I've seen Bob Kramer making one - the vid where he makes a Damascus blade from a single steel cable. This is what I thought was the dog's Damascus. I don't know how common this is, and I've only presumed when seeing certain custom bladesmith's work (the very expensive ones) that this too has no cladding. Does this method produce the swirling Damascus patterning?

Cladding - or san mai. A core 'blade' is somehow clad with 'Damascus' layering. The layering on some blades seems to be made (folded?) from more than one material?
I've just watched Jon (JKI) reviewing the Gonbei hammered Damscus and he seems to be promoting the cladding as a good thing

However, I've seen it said the feel of using this construction referred to as like wearing a condom?? I have briefly used a Shun hammered Damascus and didn't like it - thought it felt thick, sticky and plastic like

Etching and lasered. The pattern is acid formed - so no cladding, just a pattern

So, what is the best type of Damascus and is cladding all that bad?

Confused
 
Disclaimer, I am not a metallurgist. Here's what google turned up which seems a starting basic explanation differentiating between 'true' Damascus, aka wootz vs modern pattern welded steels. http://www.thearma.org/essays/damascus-steel.html#.Vm9AqXnsmpo Both sometimes get lumped under the broad title of Damascus steel.

San mai means three layers, like outer layers made of something like stainless, with a core of carbon steel just protruding on the edge. There are many variations on this type of layering, like pattern welded outer layer with a monosteel inner core. Here's a picture and lots of other info on the site: http://zknives.com/knives/articles/jpnknifecladtypes.shtml

As to what is the best type of Damascus and is cladding bad? There is no quick answer to that one. I suggest buying examples of all the different types and giving them a try. I am sure there will be lots of opinions on the forum.

:popcorn:
 
Here is an example of modern pattern welding and san mai construction:
[video=youtube;ufS-1eduLtY]https://www.youtube.com/watch?v=ufS-1eduLtY[/video]
Can't vouch for the geometry and blade shape for a kitchen knife, but seems to be a reasonable explanation.
 
Castalia said:
Del, you are a master. I am looking forward to getting one of your Damascus blades one of these days when my knife purchasing budget allows....
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They are a work of art.

To the OP the pattern isnt etchec in acid. The materials used to create the layers are picked so they react to acids (or other etchants) differently. This is how the pattern appears. At least in modern damascus.
 
I think I'm beginning to 'get-it'

In San-Mai there is no folding as such - a sandwich of outer laminated coverings (2 steels mixed together giving the pattern) with an inner (stainless/carbon), but no overall mixing

Pattern Welded Damascus is various pieces of metal twisted (or folded?) together

Cable Damascus is what Bob Kramer makes in his You Tube vid (high carbon multi-strand cable)

And then there is the Wootz Damascus which is still shrouded in a bit of mystery. Can't quite get that yet

However, it would seem the modern steels surpass all the Damascus blades in performance?

Other thing, apart from San-Mai, do the other types have a mixed composite edge of all the different metals? And does this matter or make a difference to cutting performance?
 
bonestter said:
I think I'm beginning to 'get-it'

In San-Mai there is no folding as such - a sandwich of outer laminated coverings (2 steels mixed together giving the pattern) with an inner (stainless/carbon), but no overall mixing
Click to expand...

Not quite. The outer layers of san mai can be either a single layer of soft iron or stainless, or a layer of damascus. Either way, they are forge welded around a core of carbon or stainless steel.

Pattern Welded Damascus is various pieces of metal twisted (or folded?) together

Cable Damascus is what Bob Kramer makes in his You Tube vid (high carbon multi-strand cable)
Click to expand...

Yes. Pattern-welded damascus is made by forge-welding several layers of dissimilar metals and then repeatedly folding, cutting and reassembling, and/or twisting the billet to produce a particular pattern.

And then there is the Wootz Damascus which is still shrouded in a bit of mystery. Can't quite get that yet
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No mystery at all. Wootz is steel made by mimicking the process that was used to make the historical Damascus steel. Iron ore and charcoal are combined in a ceramic vessel used to smelt the ore and produce steel. The result is then hammered and folded to remove impurities.

However, it would seem the modern steels surpass all the Damascus blades in performance?
Click to expand...

Yes, they do, from a combination of better composition and heat treating.

Other thing, apart from San-Mai, do the other types have a mixed composite edge of all the different metals? And does this matter or make a difference to cutting performance?
Click to expand...

If the knife is made completely from damascus, it will have such an edge as you describe. Whether it makes a difference in cutting performance is hotly debated. My personal experience based on damascus blades from Michael Rader, Del Ealy and Devin Thomas is that it does.
 
Pensacola Tiger said:
If the knife is made completely from damascus, it will have such an edge as you describe. Whether it makes a difference in cutting performance is hotly debated. My personal experience based on damascus blades from Michael Rader, Del Ealy and Devin Thomas is that it does.
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In so many ways, that's not helping me ;)

Seriously, thanks so much for joining the gaps I didn't quite make

So, the pattern welded process (end product Damascus) is pretty close to the Wootz (choice of metal dependent for pattern welding)? Is that a reasonable jump to make, or way off?

Also, could you comment on Coreless Damascus? Is that similar to the above pattern/Wootz in that it is folded and welded? Info elsewhere is scarcest of all on coreless, even the process involved

I'm looking at a choice of a possible custom damascus gyuto and the choice is San Mai or coreless

Much apreciated
 
bonestter said:
In so many ways, that's not helping me ;)

Seriously, thanks so much for joining the gaps I didn't quite make

So, the pattern welded process (end product Damascus) is pretty close to the Wootz (choice of metal dependent for pattern welding)? Is that a reasonable jump to make, or way off?

Also, could you comment on Coreless Damascus? Is that similar to the above pattern/Wootz in that it is folded and welded? Info elsewhere is scarcest of all on coreless, even the process involved

I'm looking at a choice of a possible custom damascus gyuto and the choice is San Mai or coreless

Much apreciated
Click to expand...

The pattern welded steel is a very different process from wootz. The pattern welding now is done with modern steels and in some instances can make an improvement in cutting performance. It is done by stacking and folding multiple layers, or starting with a lot of thin layers and forge welding them together to create the pattern.

Wootz on the other hand involves throwing everything in a pot and melting it together. The pattern there comes from high carbon crystals of steel so large you can see them.
It was made in what is now modern Turkey and Ukraine,and was called Bulat by them, and shipped through Syria, and that is how it got called Damascus. All of the early smiths used the folding and welding process to help purify the steel they made using the bloomery method. The Chinese were using blast furnaces fairly early on and doing melts of steel over 1000 lbs.
Del
 
Delbert Ealy said:
The pattern welded steel is a very different process from wootz. The pattern welding now is done with modern steels and in some instances can make an improvement in cutting performance. It is done by stacking and folding multiple layers, or starting with a lot of thin layers and forge welding them together to create the pattern.

Wootz on the other hand involves throwing everything in a pot and melting it together. The pattern there comes from high carbon crystals of steel so large you can see them.
It was made in what is now modern Turkey and Ukraine,and was called Bulat by them, and shipped through Syria, and that is how it got called Damascus. All of the early smiths used the folding and welding process to help purify the steel they made using the bloomery method. The Chinese were using blast furnaces fairly early on and doing melts of steel over 1000 lbs.
Del
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Wow

Are all the examples on your 'custom damascus' site page made this way?

BTW - I really like the rings - a lot
 
bonestter said:
In so many ways, that's not helping me ;)

Seriously, thanks so much for joining the gaps I didn't quite make

So, the pattern welded process (end product Damascus) is pretty close to the Wootz (choice of metal dependent for pattern welding)? Is that a reasonable jump to make, or way off?
Click to expand...

No, not at all. Wootz starts with a more or less homogeneous mass that is hammered, folded and hammered again, over and over to remove impurities. The pattern produced is incidental to the process. Pattern welded steel starts with pure alloys that are hammered, folded and hammered again to produce a pleasing pattern, which is a goal of the process.

Also, could you comment on Coreless Damascus? Is that similar to the above pattern/Wootz in that it is folded and welded? Info elsewhere is scarcest of all on coreless, even the process involved
Click to expand...

Coreless damascus is a term used to describe a blade that is made of solid pattern welded steel, as opposed to a san mai blade that has a monosteel core sandwiched between two layers of pattern welded damascus. The term appears to have originated with the Echizen brand of knives sold by japanesechefsknife.com and knifemerchant.com. A few custom bladesmiths have made knives like this, the three I have experience with I mentioned in my previous reply - Michael Rader, Del Ealy and Devin Thomas, and one I forgot to mention - Mert Tansu. In all four instances, I noticed that the blades seemed to hold a useful edge longer than other knives that had a single steel for an edge.

Oh, yes, I almost forgot. Shun now makes a knife series they call Dual Core - a solid pattern welded combination of VG10 and VG2 stainless. There was a passaround of one of these not too long ago that I participated in, but did not have the knife long enough to gain a valid opinion of its edge holding.

I'm looking at a choice of a possible custom damascus gyuto and the choice is San Mai or coreless

Much apreciated
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It really comes down to personal preference concerning the appearance of the blade. Some favor how the core looks "peeking out" from under the damascus, while others like the uniform appearance of the solid damascus.
 
It's the solid damascus that appeals to me

There is a custom maker based in London (as I am UK based) Blenheim Forge which caught my attention on another current thread here and they offer core and San Mai. Their damascus patterning is a real draw

While it is extremely tempting to go with the likes of Devin and get the true damascus, I could easily see costs spiraling with UK import duty and tax
 
Wootz damascus is not folded but developes carbide banding which looks like layers. It is made by smelting ultra high carbon steel with trace amounts of carbide formers like vandium, and then forged at lower temps causing the carbide banding.

To test the damascus cutting effect, me and Larrin made three test coupons, first one was aeb-l, the second was 154cm, and the third one was 100 layers of aeb-l and 154cm pattern welded steel. We tested them on a catra testin maching used to measure wear resistance. We heat treated all three to the same hardness. We found that the pattern welded material cut longer than either of the mono steel coupons. We assume that because of the different wear rates of the two materials at the edge, it causes a micro serration and cuts longer.

The Japanese like damascus more for looks than its cutting ability so they weld a core to cladding of damascus.

Hoss
 
bonestter said:
Wow

Are all the examples on your 'custom damascus' site page made this way?

BTW - I really like the rings - a lot
Click to expand...

Yes, as is all of the pattern welded steel you will see, except that specifically designated as wootz.
Del
 
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