Pattern with Value

Source: "© Frankfurter Allgemeine Zeitung GmbH, Frankfurt. All rights reserved. Provided by the Frankfurter Allgemeine Archiv, first published 20.07.2025, by Marco Dettweiler (text), Lucas Bäuml (photos)

Damascus knives stand out. Their blades have a high-contrast pattern consisting of many waves that run parallel to the cutting edge. Some specimens even have swirls or other structures. But how does Damascus steel, as it is also called, get its pattern? We made our way to a forge to take a close look at the process. You don't have to fly to Japan to do this. A car ride to Solingen to Nesmuk is enough. The manufactory specializes in high-quality knives made with special steels.

All Damascus knives from the company pass through the hands of Markus Pattschull and Torsten Schreier. They are Nesmuk's blacksmiths. Pattschull is Schreier's teacher. The apprentice's training takes several years. The forge, located on the lower floor of the building, looks as one would imagine: dark, dusty, untidy, and with a glowing yellow-red forge in the middle. Markus Pattschull does not look at all as one would imagine. He is lean and sinewy, with his hair tied in a braid. Actually, the graduate biologist could have been involved in RNA research, but now he stands with dark-tinted safety glasses in front of the anvil and skillfully and forcefully hammers a piece of steel. His work begins with this 350 × 200 × 150 millimeter block. It consists of 220 or 330 thin, welded layers of steel. The type of steels, the number of layers, and their processing with the hammer and other tools are the secret of every Damascus knife.

The fact that Markus Pattschull does not have to start from scratch and can begin directly with this package makes his life as a blacksmith a little easier. Nesmuk has the packages made in a steel mill, also because no material is lost in comparison to manual production. There, a manipulator, a giant press, presses several hundred layers together and fire-welds them at 1100 degrees Celsius. With every Damascus steel, at least two types of steel must be alternately layered. Only then can a high-contrast pattern later emerge on the blade. Nesmuk uses three different steels. The steel with a high nickel content later makes the blade shine and is more flexible than the other two steels. Nesmuk uses the type with classification 1.2419.05 for this. This rather rare special alloy has a carbon content of 1.3 percent and the same amount of tungsten. Among metals, it has the highest melting point, is shiny white, and is quite hard with a hardness of 65 (measured by the Rockwell method on the C scale).

For example, Nesmuk offers one with 28,718 layers. To achieve this, there are two methods. The original method is folding. However, blacksmiths do not use it to get as many layers as possible, but to refine the steel, i.e., to clean and ennoble it. In this process, the blacksmith places the package, which he has previously heated to about 1100 degrees Celsius, horizontally on a wedge and hammers it from above until it becomes so thin in the middle that he can fold it over the edge of the anvil to layer the two halves on top of each other. Because the same type of steel always meets in the middle, the layers add up approximately like this: 5, 9, 17 . . . 257, 515, 1029. The other method is stacking: The blacksmith takes a block with ten fire-welded layers, cuts it into about five equal pieces, then re-welds them, and has stacked fifty layers. Do this again, and he's at 250. This method is faster because the blacksmith halves the number of fire-welds compared to folding.

However, Markus Pattschull is not interested in layer-stacking records. He wants to create a creative pattern. For this, he always welds several blocks together. Each individual layer package has usually already been processed with one or more methods. The blacksmith has a large selection to do only one thing: to disrupt the order of the initially uniformly layered steel sheets. Anyone who used to play with modeling clay can imagine it better. For example, if you stack three black and three white rectangular plates on top of each other and press down on one spot, the layers below shift. Now you can take the block in your hands and turn the respective ends in different directions with your left and right hand. Or you can place the block on one of its long edges and hit it from above with your hand. The blacksmith also has all these possibilities of deformation with the hammer. The only difference is that the layers are inseparably connected due to the heat.

At the end of these deformations, the blacksmith has a flat, rectangular piece of steel in front of him, consisting of twisted and shifted layers, from which the final knife shape still has to be separated. For the unique pieces of the C150 series, Markus Pattschull makes one knife from one piece. For this, he hammers it into its final shape on the anvil. The blade is forged out, the tang is notched, and bevels are created. For other series, which do not have such elaborate mosaic patterns because Pattschull used fewer deformation techniques, the layered Damascus is produced in larger pieces, so that several knives can be made from it. For the C90 and C100 series, Nesmuk always has two or four knives cut by laser from a Damascus steel plate by a specialist in Solingen. It is then rolled out to five millimeters, hardened, and then shrinks to four millimeters due to the removal of the oxide layer.

For every knife: Before the fine grinding, each blade must be hardened. For this, the blacksmith heats it to 800 degrees Celsius so that the crystal structure changes, only to cool it down quickly immediately afterwards and then temper it, i.e., heat it up again to about 200 degrees Celsius.

Until now, the Damascus knife is only finished in its shape; the pattern can only be guessed, contrasts are barely present, the difference to a monosteel knife is small. And then Markus Pattschul dips the knife into a bath of iron(III) chloride solution. The acid attacks the steel; it reacts with the surface. Since it is composed differently, the acid attacks one steel more than the other. The acid reacts less strongly with the nickel, i.e., the soft layer, so that it retains its silver-shining appearance. The solution acts more on the other steels, making them darker. Like a magic trick, a complex pattern appears on the blade after the acid bath.

To ensure that contrasts and gray tones remain as pure for years, Nesmuk, together with scientists from the Fraunhofer Institute, has developed a process that protects the blade from oxidation. The steels would be susceptible to this due to their carbon content. Because the blade is not stainless, without this protection, at least a patina forms, which no longer looks as nice. However, an alloy with chrome, which does not rust, is not an alternative, because such steels have lower cutting performance. Nesmuk wants knives with maximum sharpness. Therefore, before selling them, the company sends all Damascus knives in a vacuum-sealed sheath to a specialist who coats them in a chamber with a microscopically thin layer of glass. The blade is then protected from contact with oxygen, and the steel does not react.

Nesmuk itself shows in its product range that specimens made of Damascus steel, despite all the effort, are only more beautiful but not sharper in use than monosteel knives. Even the models of the "affordable" Soul collection are among the sharpest knives we know. They just don't stand out as much.