Sorry to bother you, but I’m looking for a dagger that (I think) was mentioned on this tumblr. I can’t for the life of me remember what it’s called. I remember that how they were made has been lost, and that the blades have swirly patterns on them. I also know that there are only so many of them left.
You’re probably talking about Damascus steel. Technically, this wasn’t just used for daggers, there are some surviving swords as well. Damascus steel is part of a larger family of historic alloys called crucible steel, because of how they were produced. While we can easily produce crucible steels today, the specific process that produced Damascus steel was lost sometime in the 18th century.
I’m not an expert on smelting, so I’m probably going to botch some of the details here, but the basic idea with crucible steel is that you take multiple forms of iron or steel, usually of significantly different carbon content, stick them in a sealed clay receptacle (the crucible), and then melt them together into a solid slug. This often includes adding impurities into the material in the process to adjust the carbon content, or into introduce additional materials into the alloy, such as nickel. Because the metals have different melting points, the resulting mixture will not mix completely, and the result is a “banded” or “wood grain” pattern. (If you’d like to see some professionals smelting crucible steel, and forging it into a blade, the guys at Baltimore Knife and Sword had a Man at Arms Reforged video last year, where they created a replica Ulfberht.)
Research in the last couple decades has suggested that authentic Damascus steel was actually a superalloy, with carbon nanotube structures. While the smiths working it wouldn’t have known about that, the resulting metal did have exceptional characteristics that made it famous, and drove demand.
Specifically, Damascus steel weapons were renowned for being unusually durable, and applicable of holding very fine edges. As a result, their survival rate is pretty good in comparison to contemporary weapons. (That said, there aren’t a lot left, you’re correct about that.)
While there have been numerous attempts to replicate Damascus steel, to the best of my knowledge, none of those attempts have yielded similar compositions. Modern “Damascus steel” knives and swords replicate the visual appearance, and may actually be crucible steel, but lack the incredible durability, and hardness of the original examples.
The name itself is a little bit of a misnomer; while the smiths who forged weapons from the metal were in Damascus (or at least in the Middle East), but the material itself came from India via trade routes (and the technique originated in Sri Lanka sometime in the third century.) So, the forging techniques weren’t, really, lost. However the supply ceased. It’s unclear what the cause was. Theories include failure to transmit the process to new smelters, loss of some critical ingredients, the British Raj, and eventual occupation of India, or some combination of the above.
A lot of the time Damascus steel gets described as a lost technique, and that’s, kinda, true. But, it would be slightly more accurate to say, “we lost the recipe.” We still know how to make crucible steel, and we can certainly still forge weapons, but the exact process that resulted in that variant is lost.