[ariel]

Many sources incorrectly classify Kirk Narduban ( "40 steps") as a separate variety of Wootz, along with Khorasan, Taban, Shams etc.
Nothing can be further from the truth.
Kirk Narduban is not a variety of Wootz, it is a decorative element artificially created by the bladesmith. To get it, the smith chizels the grooves into the body of the blade, distorting the Wootz structure and then heats and pounds the blade. The famous steps are just the result of distorted Wootz patterns.

Kirk Narduban can be easily created as just parallel steps, zigzagz, double steps, kirk and rose , double kirk and rose or whatever. It can be created using whatever variety of Wootz the blade consists of: there are Shams blades with it. In a way it is somewhat similar to any other superficial embellishment , such as koft or zarnishan. Old metallurgists took a lot of time to understand the technique of Kirk Narduban, attributing it to inherent Wootz structure, but the "secret" was much simpler.

Even the wootz structure is in a way artificial: the inherent dendrites within the ingots can be arranged as straight lines, curly lines, wavy lines etc. by a skillful smith pounding the ingot with different force and in different directions. Pay attention to the most sophisticated Wootz blades: the body has complex patterns, but the edge always shows straight, - Shams-y,- lines, the result of intense pounding to thin that part of the blade. Wootz ingots were manufactured in India in tens of thousands per year and sold all over the Islamic world, but in each locality there were established traditions of smithing, explaining why Persian blades were largely Taban or Khorasan, but the Mamluk or Ottoman were Shams. Older Indian Wootz has not lines, but a "grainy" structure: these are dendrites subjected to extra intense pounding that was breaking them into small segments ( what modern smiths call spheroidization). I was told that Indian Wootz blades were superior to the Persian from the mechanical point of view. Indian bladesmiths acquired the sophisticated Persian techniques sometimes around 17th century, learning them from the Persian masters imported to the Mughal courts. It is the main reason why modern bladesmiths still cannot make the sophisticated patterns.

The quality of Wootz blades vs. good European monosteel is another matter: they could not withstand cold, they shattered easily, and their hardness was low: ~20-25 Rockwell units. Make it simple, stupid:-)))