When Was the Iron Age, Really? What Was Ancient Damascus Steel, and What is Modern Damascus Steel?

     This entry will be discussing a journal paper from Journal of Materials Processing Technology Volume 117, Issue 3, 23 November 2001, Pages 347-353 entitled Ancient blacksmiths, the Iron Age, Damascus steels, and modern metallurgy by authors Oleg D.Sherby Jeffrey Wadsworth. Why this?  Well, dear reader, blacksmithing just happens to be a hobby of mine and metallurgy is an area I hope to place some focus on in the future, so it’s only natural that I would gravitate toward an engineering paper on this topic. It was a fun read that covered a number of different aspects pertaining to blacksmithing, metallurgy, and Damascus steel, as well as challenging the notion of when the Iron Age actually started, which is what I will discuss first.

It is believed that the Bronze Age began around 7000 BCE, lasting until the start of the Iron Age around 1200 BCE. What denotes the beginning of the Iron Age was when iron began replacing the bronze weapons and tools of the time. This paper questions when the Iron Age actually began, and suggests it came prior to the Bronze Age for a number of different reasons. The first notion points out that iron would have been much, much easier to work with due to it not being an alloy that needs melting temperatures to produce, while bronze required three separate melting procedures and a combination of metallic ores to create. This would have been quite difficult to achieve at that time due to primitive technology. The second noton is based on evidence that iron was being used long before bronze, as evidenced by findings of iron items dating prior to any bronze findings, including an iron plate that was incorporated into the Great Pyramid during its construction around 3000 BCE. Dating back even farther, one of the last remaining Neanderthal sites near the town of Ortigosa, Spain, is believed to be an extensive mining site where an abundance of ochre, which is iron oxide, is inconsistent with the notion that iron was not extensively used. 

The paper then goes on to explain ancient blacksmiths and their understanding of ironworking. Sherby and Wadsworth explain the 5 mental tools ancient blacksmiths utilized for this process. The first being observation of color as iron is heated for forging and heat treating. The second is determining the strength of iron based on ease of forging in relation to its color when heated. The third is using methods of scratching and bending the iron to determine its strength and hardness at ambient temperature. The fourth is the use of lodestone to measure the magnetic qualities of iron. The fifth, and last, is understanding of iron’s “two distinct internal structures, a compact one and a less compact one.” All of these tools are still utilized today.

Sherby and Wadsworth go on to describe what I recognize to be the ancient formation of steel by adding charcoal (carbon) to iron, then further delves into the process by presenting a diagram supposedly used by ancient blacksmiths representing the properties of heated iron in relation to their color and amount of added carbon. To add my own theory to theirs, considering that carbon decreases the melting point of steel/iron, this may have been the original purpose for adding charcoal to iron. An added benefit to doing this was that it increased the hardness of the steel significantly, allowing tools and blades to be produced that held a sharpened edge much better than wrought iron (iron without carbon). 

The paper then segues into the topic of Damascus steel. Now, typically when I write these blog posts, ALL of the information I present is from the main source.  However, the one photo example of Damascus steel Sherby and Wadsworth present in their paper is, pardon me for saying, mostly useless, especially if the reader has no previous knowledge of what Damascus looks like. It’s beautiful, so I have found some images to include in this post from various areas of the internet; forums, image searches, where-ever.  Due to this, my citing is likely going to be poor, so if you just happen to be the owner of these images, please send me some proof and a citation to use that gives you proper credit.  But enough of that, let’s look at some Damascus, then I’ll tell you what it is.

Figure 1: Damascus “Dane Axe” by Owen Bush.

Figure 2: Feather Pattern Damascus by Vetus Knives.

Figure 3: Various popular Damascus patterns compliments of Devin Thomas.

More complex “Damascus” style pattern welds have emerged over time, utilizing complex mathematical formulae to arrange different types of steel to create “mosaic” patterns like the blades in the following images:

Figures 5 and 6: Mosaic “Damascus”/”Pattern Welded” blades that were reposted too many times on BladeForums.com for me to locate their origin.

To further nerd out on knives, here are some examples of Damascus/Pattern Welded/Mosaic blades that, when treated with hot water containing “salts,” take on some marvelous color. Behold:

Figures 6 and 7 are samplings of colored Damascus knives from the Vallotton family of knifemakers.

See what I mean by how beautiful “Damascus” is? Now I’ll tell you what it is, and to give a spoiler: nothing you see on these blades has been painted or drawn on. 

Damascus steel, as described by Sherby and Wadsworth, was the game given to “wootz” as it was known as in India, or “bulat” as it was known as in Russia, or “pouhad Janherder,” as it was known as in Persia, where it seems to have been the most popular due to its extensive use by Persian blacksmiths in forming swords and other weapons. This was made by combining two (or more) ultrahigh carbon steels (UHCS’s), supposedly containing 1% to 2.1% carbon, which is around as much or more carbon as the high carbon steel used in knives today (over 2% carbon bears often undesirable results due to contaminants, and is the point where steel becomes cast iron). Somehow, this method produced a very hard, yet tough, edge weapons that held a very sharp edge very well and was exceptionally hard to break. Unfortunately, this method is a lost art, and attempts to duplicate it have, so far, not produced anything comparable. This legendary steel was more valuable than gold at the time, and based on practical usage, I can certainly see why. 

Modern “Damascus” steel, also referred to as “pattern welded” steel, combines a high carbon steel with a steel with less carbon, often medium carbon steel or even low carbon steel if the item being made will be used as an impact tool or needs very high contrast for aesthetic purposes. Nickel is a popular material to use in layers along with the steel, or a steel that contains nickel is used, such as 15N20. The different materials, usually around one eighth to quarter inch thick, are stacked in an alternating pattern and “forge welded” together. Forge welding is where two pieces of metal are heated up almost to their burning point, then placed atop each other, and pressed or hammered together, fusing the two pieces together into one. In this case, an entire stack is forge welded at once. After the stack is fused together, it is then hammered flat once again to its original thickness, forming a flat bar referred to as a “billet.” Sometimes this is the end of the process for forming the Damascus billet, but usually it is not. The billet is then either folded in an accordion type shape, or cut back into individual pieces and re-stacked, and the process is repeated as many times as necessary to reach the layer count the maker desires, until it is finally formed into the billet, which will serve as the starting material for whatever item is being forged, such as the knives pictured. (There are other ways to produce Damascus, such as in canisters, but I want to leave some things for you to look up yourself.)

In this state, the billet will look the same as any other steel billet- a light gray color, with uniform surface consistency and no pattern. To get the pattern to show, the billet must be etched in an acid, such as ferric chloride. This is where the magic happens. Harder materials such as the higher carbon steel and especially steels containing nickel, take a lot longer for the acid to etch into it, if it will at all. The softer, lower carbon steel, however, will respond to it much faster, not only turning it grey or even black, but if etched long enough, it will eat that softer steel away which will then be recessed lower within the billet’s surface than the harder steel or nickel. The surface can then be polished, but the softer steel will not be level, thus will not get polished. The result is the harder/nickel steel being bright white/silver, while the softer steel remains dark, creating a beautiful contrast and preventing the darker steel from wear and allowing the contrast to last longer.

Unfortunately, modern Damascus doesn’t result in the same super-hard blades that hold an unparalleled edge as ancient Damascus did, but it still makes the blades quite durable due to the combination of the hard, potentially more brittle steel and the soft, tough steel. It’s still great to have, but if it is a knife one actually uses regularly rather than kept unused as a collectors item, it may need to be sharpened often due to the low hardness of the softer steel. That is, unless two higher carbon steels are used that can be heat treated without conflict, thus resulting in uniform hardness and better edge retention.

As for the photos, Fig. 1, the image of the “Dane Axe,” is a very nice random Damascus pattern that has enough contrast to show the pattern, but the softer steel must not be that much softer than the harder steel. This means the axe will likely hold a very good edge, while having some softer qualities to prevent brittleness, that make it great for chopping things at full force as one typically does with an axe.

Fig. 2 is a kitchen knife by Vetus Knives with a feather Damascus pattern, which is a very popular pattern in the knife world. The contrast is very high between the two metals due to consisting of the nickel-steel 15N20 that was previously mentioned, along with 1095 steel, pounded and folded to reach 365 layers. Due to both of these steels’ higher carbon content, .75% and .9-1.05%, respectively, this knife likely holds a fine edge, while the etchant resistant nickel allowed for the high contrast.

Fig. 3 is a collection of patterns as demonstrated by Devin Thomas, that are popular among Damascus makers, while Figs 4 and 5 are significantly more complex “mosaic” pattern welds that really change the game when it comes to Damascus. The possibilities for patterns are only limited by one’s imagination and mathematical skills, as they require very precise calculations to produce the intended pattern. My bladesmithing instructor, Master Bladesmith Ray Rybar, goes so far as to create words within his Damascus patterns.

Figs. 6 and 7 are still Damascus, but I included them simply as a bonus to show the possibilities of Damascus in decorative form. The color is not painted onto these blades, but rather caused by a thermochemical reaction when the blade, which would already be fully heat treated (hardened and tempered), is exposed to hot water containing “salts” for various durations until the desired color is achieved. Note that the different metals take on different colors, naturally, creating the contrast evident in these samples. These are typically collectors blades since the color will otherwise wear off with use, and the heat from the coloring process likely softens the blades, resulting in poor edge retention.

Was that a treat, or what? Please tell me you didn’t already know all of this or at least that you enjoyed looking at those photos.  Lie to me if you must! 

 

Now, I certainly encourage you to read the original journal paper by following the doi in the work cited section of this blog entry so you can find more detailed information on what was discussed. If you’re looking for information on modern Damascus as I have explained it, however, you will have to look elsewhere since I freestyled most of that from my existing knowledge, and I still have a LOT to learn about it. So get to digging for all of that information I know you’re itching to expand your mind with. If you dig deep enough that you find yourself wanting your very own custom Damascus knife, dear reader, keep me in mind as I would love to make one for you (shameless self promotion is shameless), as would any of the amazing (and far more experience than myself) knifemakers referenced in this blog. Just be aware that the price tag can be quite steep.

Work Cited

Sherby, O. D., & Wadsworth, J. (2001). Ancient blacksmiths, the iron age, Damascus steels, and modern metallurgy. Journal of Materials Processing Technology, 117(3), 347–353. https://doi.org/10.1016/s0924-0136(01)00794-4 

Images:

Bush, Owen https://www.owenbush.co.uk

Thomas, Devin http://www.devinthomas.com

Vallotton Custom Knives http://www.valknives.com/ (as found on https://www.knifeblog.com/ and http://www.bladehq.com) 

Vetus Knives https://www.vetusknives.com (as found on https://www.arizonacustomknives.com/)