Damascus steel

Damascus steel is a type of steel alloy that is both strong and malleable, a material that is perfect for the building of swords. The process was used for only a short time between about 1000AD and 1300AD in the middle east[?], and then disappeared for reasons that are not entirely understood. It is said that when it was first encountered by Europeans during the Crusades it garnered an almost mythical quality – a Damascus steel blade was said to be able to chop through normal blades, or even rock, without losing its sharp edge.

When forming a batch of steel, impurities are added to control the properties of the resulting alloy. In general, notably during the era of Damascus steel, one could produce an alloy that was strong and brittle at one extreme by adding about 2% carbon, or soft and malleble at the other, with about 1% carbon. The problem for a swordsmith is that the best steel should be both stong and malleble – strong to hold an edge once sharpened, but malleble so it would not break when hitting other metal in combat. This was not possible with normal proccesses.

Metalsmiths in India as early as 300BC developed a new technique known as Wootz steel[?] that produced a high-carbon steel of unusually high purity. Glass was added to the mixture of iron and charcoal, the glass would bond with impurities in the iron stock and then float out while the mixture cooled. The technique moved very slowly though the world, reaching modern-day Turkmenistan and Uzbekistan around 900AD, and then the middle-east around 1000AD.

In the middle east the process was further refined, allowing the carbon to precipitate out primarily in the center of the blade, thereby producing a softer center with very strong edges – the swordsmith's ultimate goal. The carbon precipitate in the center leaves the blade covered with a beautiful swirling patterning, apparently the origin of the term damasque[?].

For reasons that are not entirely clear, the process was then lost to the middle-eastern metalsmiths around 1300AD. The exact nature of this method was then lost to time, and the "secret" of Damascus steel has been sought ever since. Recently a metallurgist and a chemist have claimed that they have recreated the process, but even they admit they do not understand how it was originally created. Even with modern equipment and techniques, apparently 1 in 4 batches fail.

For some time it was believed that Damascus steel was made in a similar fashion to what is known as pattern welding, a sword making technique that was widely used in Europe and Japan. Pattern welding is a mechanical process that lays up strips of material which are then pounded together, or folded, as in Japanese practice. If the blade is then etched in acid the layering below the surface is revealed, the patterns being similar to that of Damascus steel. For some time this similarly was used to dismiss Damascus as yet-another pattern-welded steel, but modern metallurgy demonstrated this to be wrong.

It has also long been argued that the raw material for Damascus steel swords was imported from India, because India was the only known center of crucible-fired steels like Wootz. However this too proved wrong when the furnaces in Turkmenistan were recently discovered, demonstrating at least that the technique was moving out from India. There appears to be no reason to suspect that similar metal factories were not built in Damascus, although had they been the disappearance of the technique requires explaination.

Another common myth is that that Crusaders introduced the term to Europe after meeting it in combat. However several historical studies have demonstrated that the term did not appear in English until the 16th century.

Even the name itself remains somewhat controversial. Although it would seem obvious that it refers to swords build in Damascus, there are several equally likely sources. One is the Arabic word damas for water, referring to the surface pattern that looks like turbulant water. Another potential source is the swordsmith himself, the Islamic author al-Beruni refers to swords made by a man he names Damasqui. Finally another author, al-Kindi, refers to swords made in Damascus as Damascene.

So, after a 1000 years, Damascus steel remains something of a mystery.

See pattern welding, sword

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External links and references:

• J. D. Verhoeven, A. H. Pendray, and W. E. Dauksch, The Key Role of Impurities in Ancient Damascus Steel Blades, JOM 50 (9) (1998), pp. 58-64.
  • Online edition: http://www.tms.org/pubs/journals/JOM/9809/Verhoeven-9809