Pattern with value

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

Damascus knives stand out. Their blade has a high-contrast pattern consisting of many waves that are distributed parallel to the cutting edge. Some knives even have curls or other structures. But how does Damascus steel, as it is also known, get its pattern? We made our way to a forge to take a closer look at the process. You don't have to get on a plane and fly to Japan to do this. All it takes is a car ride to Nesmuk in Solingen. The manufactory specializes in high-quality knives with special steels

All of the company's damask knives pass through the hands of Markus Pattschull and Torsten Schreier. They are Nesmuk's blacksmiths. Pattschull is Schreier's teacher. The student's training takes several years. The forge on the lower floor of the building looks just as you would imagine: dark, dusty, untidy and with a glowing yellow-red forge in the middle. Markus Pattschull doesn't look anything like you would imagine. He is thin and sinewy and has his hair tied back in a plait. The biology graduate could actually have been doing research into ribonucleic acid, but now he is standing in front of the anvil with dark-tinted safety goggles, skillfully and powerfully hammering away at 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 steel, 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 doesn't have to start from scratch and can begin with this package right away makes his life as a blacksmith a little easier. Nesmuk has the bundles made in a steel mill, partly because no material is lost in the process compared to manual production. There, a manipulator, a giant press, presses several hundred layers together and fire-welds them at 1100 degrees Celsius. For each Damascus steel, at least two types of steel must alternate on top of each other. This is the only way to create a high-contrast pattern on the blade. Nesmuk uses three different steels. The steel with a high nickel content later makes the blade shiny and is more flexible than the other two steels. Nesmuk uses the grade with the classification 1.2419.05. This rather rare special alloy has a carbon content of 1.3 percent and the same amount of tungsten. Among the metals, it has the highest melting point, is shiny white and quite hard with a hardness grade of 65 (measured according to the Rockwell method on scale C).

Nesmuk, for example, offers one with 28.718. There are two ways to get there. 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 refine it. In this process, the blacksmith places the package, which he has previously heated to around 1100 degrees Celsius, crosswise on a wedge and hammers on top until it becomes so thin in the middle that he can fold it over at the edge of the anvil so that the two halves can be placed on top of each other. Because the same type of steel always meets in the middle, the layers add up 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 to weld them together again, and then stacks fifty layers. This process is quicker because the blacksmith halves the number of fire welds compared to folding.

But Markus Pattschull is not interested in setting records in layering. He wants to produce a creative pattern. To do this, he always welds several blocks together. Each individual layer package has usually already been processed using one or more methods. The blacksmith has a large selection to choose from in order to do just one thing at a time: to bring the layers of steel, which initially lie evenly on top of each other, out of order. Anyone who has played with plasticine in the past will have a better idea. For example, if you stack three black and three white rectangular plates on top of each other and press on one spot at the top, the layers underneath will shift. Now you can take the block in your hands and turn each end in different directions with your left and right hand. Or you can place the block on one of the long edges and hit it with your hand from above. The blacksmith also has all these deformation options with the hammer. The only difference is that the layers are inseparably bonded together due to the heat.

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

The following applies to every knife: each blade must be hardened before the fine sharpening stage. To do this, the blacksmith heats it to 800 degrees Celsius to change the crystal structure, then cools it down quickly and heats it again to around 200 degrees Celsius in the next step.

So far, the Damascus knife is only finished in its shape, the pattern can only be guessed at, there is hardly any contrast, the difference to a knife made of mono-steel is slight. And then Markus Pattschul dips the knife into a bath of iron(III) chloride solution. The acid attacks the steel, reacting with the surface. As it has a different composition, 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 shiny silver appearance. The other steels are more affected by the solution and become darker. As in a magic trick, a complex pattern appears on the blade after the acid bath.

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

Nesmuk itself demonstrates in its range that, despite all the effort, Damascus steel knives are only more beautiful, but no sharper than mono steel knives. Even the models in the "affordable" Soul collection are among the sharpest knives we know. They just don't stand out as much.