First of all, what exactly is the difference between "iron" and "steel"?

In everyday life, you might not think much about it. You'd probably just vaguely assume they're similar things, right? However, the two are quite distinctly different.

In both a broad and narrow sense, iron is the element with atomic number 26.

I said steel and iron are different, but in the broad sense, they're both "iron". That's because the main component of steel is iron. "Steel" generally refers to what we call "Carbon steel."

Carbon steel is an alloy made primarily of iron, with a carbon content ranging roughly between 0.3% and 2%.

The Japanese word for steel, "hagane," etymologically apparently originates from "ha-gane" (edge-metal), meaning the blade material of Japanese swords.

When people think of the material for a Japanese sword, they usually think of "tamahagane" (Jewel Steel), but that's actually a name used from the Meiji era onward. I don't know what they called it before then—maybe just hagane, or perhaps they just treated it as "really good iron."

Japanese swords themselves have a very old history, but in the era of 'Old Swords'—roughly before the Edo period began—swords were made using iron from all sorts of sources.

Before the country was closed to foreign trade, imported iron was available, as well as small amounts produced locally in rural areas. There are even records of meteoritic iron being used.

Basically, it seems that imported "nanban-tetsu" (foreign barbarian iron) was often decarburized at local tatara furnaces to turn it into steel for use.

In any case, there was a great diversity of materials back then. But from the Edo period onward, with the country's isolation policies, iron supply couldn't keep up with demand.

As a result, the Shogunate took the lead in iron production, resulting in the steel used for Shinto (New Swords). At that point, the diversity of the base materials was largely lost.

Furthermore, many techniques failed to be passed down (likely because some forges went out of business when they couldn't get materials), meaning much of the knowledge from the Koto period was lost to time.

Even today, it's common knowledge that the best Japanese swords are old ones.

Of course, even among old swords, there are good and bad ones. There were probably Edo-period swords made using ancient materials and forging methods, and plenty of poorly made old swords too. The same can be said for works from the new sword period onward.

But the vast majority of surviving famous swords classified as masterpieces are old ones, and it's said that even today, we can't reproduce them.

It's what you'd call a lost technology.

Fundamentally, old things tend to have the "good ones" survive longer. Especially since Japanese swords were sometimes used as weapons—the worse ones would have been weeded out and lost through actual use.

Also, swords forged by master smiths were in high demand and expensive. The more expensive they were, the more carefully they were preserved, increasing the chances of them surviving to later generations.

However, after the peaceful Edo period, when wars ended, the demand for Japanese swords shifted more toward art objects rather than weapons. So it's debatable whether the surviving swords are truly "good as weapons."

In that sense, perhaps old swords hold particular value.

Well, even in the Edo period, old swords were popular, and there were stories of fakes circulating even then—so it's not necessarily true that only the good ones survived.

By the way, I enjoy making knives as a hobby.

I haven't made any since coming to this world, but before that, I made about two per year.

The Bowie knife I gave to Shello-san was my own work, and the knife this Dwarven Master was investigating was one I had made and sold to the Meeker Company.

They're just items made by an amateur—nothing special. But the materials are top-notch. The blade material, ATS-34, is a high-end Japanese steel for knives, and the handle material is Micarta, a synthetic material from the US.

The master said he wouldn't have retired if he had steel like that; I'm just glad it's recognized as good material in this world too.

When I make knives as a hobby, I use stainless steel 100% of the time. No exceptions. Whether it's 440C, ATS-34, VG-10, or Ginsan, they're all stainless. The defining feature is the chromium content (13% or more), which makes them rust-resistant and gives them a mirror-like shine.

I produce them using the Stock Removal method, popularized by the "God of Knives," R.W. Loveless. Essentially, you take a flat bar of steel and grind it into the shape of a knife. There's no "blacksmithing" involved in this process; it's more like machine work—grinding and polishing. Even a NEET like me can do it for a reasonable cost.

But what about carbon steel? I almost never use it for stock removal. Usually, carbon steel is used for the traditional image of knife-making: heating the metal until it glows and hammering it into shape. That is forging.

Any knife enthusiast yearns to try forging at least once. But very few custom knife builders actually take that step.

I brought a significant amount of Yasuki Steel "Aogami No. 2" with me.

Aogami #2 is a carbon steel. Technically, it has small amounts of chromium and tungsten, but it's categorized as carbon steel. As I explained, steel is an alloy—it's not a "natural" substance like gold or copper. It's a product of human research, and Japanese steel is world-class.

Among them, Yasuki Steel by Hitachi Metals holds a legendary status. It's a "wa-ko" (Japanese steel) made from iron sand or sponge iron. Hitachi Metals even researches and produces tamahagane, and their "Aogami #2" is said to be very close in properties to that ancient steel.

I'm obsessed with blades, so I naturally like Japanese swords. I've even thought about buying one and did a lot of research. That's how I learned that the world of Japanese swords is... extremely complicated.

For a sword, "good" means unbreakable, unbendable, stays sharp, and doesn't rust. "Unbreakable" and "unbendable" are tricky because they require a balance of hardness and toughness—traits that usually contradict each other.

The reason I bought "Aogami #2" for a high price (about 50,000 yen for a few swords' worth) was purely out of curiosity. I wanted to see what kind of sword a master could forge using high-end modern cutlery steel.

Yes, it's a total indulgence! But there's a reason.

In modern Japan, you are not allowed to own a Japanese sword as a "weapon." They are strictly art pieces. Owning a weapon is a violation of the Firearms and Swords Control Act. Anything over 15 cm is a "sword." Since the Akihabara incident, even daggers are banned for simple possession.

But you can own a katana. Why? Because after the war, to protect them from being confiscated by the Allied forces, people argued they were "art pieces," not weapons. They are registered as art.

However, this comes with strict shackles:

1. A blade is only legally a "Japanese sword" if it's made using old traditional methods.

2. Therefore, you must use tamahagane.

3. You cannot use Aogami, Shirogami, spring steel, or stainless steel to make a katana. It's illegal.

4. Even the smiths are licensed and can only forge 24 blades a year.

But in this different world, none of that matters.

Having a sword forged using supplied materials is perfectly fine. It won't be a Japanese sword—but I was never particularly devoted to Japanese sword mythology anyway, and honestly, I feel like a dwarf could make something better than a mediocre swordsmith.

Modern swordsmiths mostly create swords as art, after all. Comparing them to blacksmiths in a world where weapons are genuinely needed is unfair. Modern swordsmiths can't realistically hold the perspective of "Is this actually viable as a weapon?"

In this world, weapon performance is a serious matter. There are wars between humans. Bandits appear. Magical beasts and monsters appear. "This didn't cut" or "It broke" just won't cut it.

In that sense, the required performance as a weapon might be even higher than for swords from the Warring States period. Necessity is the mother of invention, as they say.

Besides tamahagane, there are other somewhat fantastical stories about Japanese swords.

For example, there's the folding technique in Japanese sword making—the thing where they repeatedly fold and forge the iron to make a strong, tough steel.

But this is a misunderstanding. That is simply the work of mixing the iron to make it uniform. It might be similar to bread making. I have a GOPAN! at home that I bought but just left sitting there unused, but anyway, you won't get delicious bread unless the ingredients are mixed and uniform.

...The conversation has jumped in a strange direction, but anyway, they hammered primitive, difficult-to-use iron or plunged it into water to drive off impurities or even out the components. Adjusting the carbon content in particular must have been essential.

In short, they were using tricks to adjust iron with poor character to make it what they wanted. Of course, this in itself is a great technique. But if the base steel is already good, that process isn't necessary.

According to experiments, there's a story that strength increases with up to two folds, but that is a completely different story from fold-forging.

Well, as an art piece, it's apparently important for patterns to appear through fold-forging to make it look cool, so it seems to be an essential process for a Japanese sword as an art piece. There's also "laminated construction": wrapping soft core iron in hard jacket steel for hardness without brittleness.

But with good steel, a solid monosteel blade should be more than sufficient. In fact, wartime military swords made this way reportedly performed better than poorly made traditional swords.

If that's the case, then that's enough. It's not like I want to make an unparalleled masterpiece.

In reality, there are plenty of Japanese-style blades overseas made from modern steels—but importing or owning them is extremely difficult. In Japan, where the Firearms and Swords Act is strict, a katana is almost as illegal as a gun.

By the way, the "Aogami #2" (Blue Paper) I brought this time is the name of the steel. Since there's a #2, there's naturally a #1.

There's the basic "Kigami" (Yellow Paper), the "Shirogami #2" (White Paper #2) made by removing impurities from that, the "Aogami #2" with added chromium and tungsten, the "Aogami #1" with increased carbon content for higher hardness, and even "Aogami Super" with extra tungsten and carbon.

Personally, I wanted to bring Aogami Super.

Regardless of practicality, I wanted to see the reaction to that incredibly hard steel. Since it's a high-tech steel, I'm curious about a dwarf's reaction...

But it was impossible.

Because it's insanely expensive.

Incidentally, Aogami Super is extremely hard, highly wear-resistant, and holds an edge incredibly well—but precisely because it's so hard, it's prone to breaking, making it unsuitable for swords. From a practical standpoint, Shirogami—said to be closer to tamahagane—might've been better. Even spring steel might have been a better choice.

Because modern blade steels are optimized for short blades like kitchen knives, it's unclear how suitable they are for swords.

Still, Aogami contains chromium, so it's somewhat more rust-resistant, and edge retention should be good. In reality, we probably won't use them much anyway, so as long as it looks beautiful and has some impact, I'll have nothing to complain about. Well, if it's made of Aogami, it should at least be on par with a sword of decent performance, and you could say that's more than enough.

Though, to be clear, Aogami #2 is an excellent and high-grade steel.

Actually, since this is a world where "Japanese swords" don't exist, I'm planning to have it made as a single-edged straight sword—something like Prince Shōtoku's Seven-Starred Sword—pure romance. Of course, if possible, I wouldn't mind having a curve put in. For the others, maybe I'll just go with normal longswords. Hard to decide.

...Well.

Romance is nice, but Elepipi's weapon needs to be fully practical. That'll require consultation.

And above all, the most fundamental issue is that sharpness ultimately depends on the user's skill. I train with swords, but I haven't trained in actually cutting things, after all.

I lined up the steel bars, which weighed several kilograms, and then pulled out eight bottles of alcohol.

They were aqua vitae—the water of life. In other words, whiskey.

Based on the simplistic stereotype that "dwarves love booze," I had bought a large quantity of the cheap stuff at a discount shop. A total of eight liters. Since it was a blacksmith shop and I figured there would be many dwarves, I decided to splurge.

Originally, I'd thought about getting an even cheaper kind that came in plastic bottles, but I figured it would be a hassle if they started asking questions about how the plastic was manufactured, so I decided against it. Then again, even glass bottles are probably the result of far too advanced manufacturing technology from this world's perspective. They do have glass bottles here, though.

In any case, I had always planned to bring alcohol. I had an ulterior motive: if we became friends, I could get them to make items for me to put up on the online auctions.

At first, I had planned to bring less, but since it fit in my inventory, I brought a large amount. This "Item Box" is much more of a cheat than an appraisal ability...

"This is, well... I'm basically a first-time visitor here, so consider it a small gesture. Please drink it together. I hope it suits your taste."

I said this with my best attempt at a smile while setting out the booze.

"Are you sure? That's a lot."

The master smith's gaze clearly said, This stuff must be expensive, right?

Well, it's certainly not cheap—though it's only about 1,000 yen per liter. However, in this world, even items from a 100-yen shop can be sold for quite a high price. That means I can't just say it's cheap because it's only worth 8,000 yen.

The fact that I could buy it for 8,000 yen in Japan is irrelevant. The value of this alcohol in this context is whatever price it would fetch if sold here. So, by this world's standards, this is expensive liquor. Since I haven't actually sold it, I don't know the exact market price, but it should be plenty.

Well, it's not a bad upfront investment.

Next, the master smith picked up the steel I'd brought—Aogami #2. He held it in his hands and closed his eyes. Cradled in his thick, rough, reddish-brown palms, the steel looked almost like a baby. It was as if he were listening to the voice of the metal itself.

"...You're giving this to us too?"

After a while, he opened his eyes and murmured softly.

Well, not exactly "giving"—I want you to make a sword with it.

"No, I want you to forge swords with it. Well, only if you like it."

He seemed to like the stainless steel from my knife, but I didn't know how he'd feel about the Aogami. If it didn't work out, so be it.

The master respectfully placed the steel back on the table, returned to the forge area, and suddenly bellowed.

"Hey, you lot! Anyone with free hands, get over here! This gentleman has brought us iron and booze! And the finest quality of both!"

At the master's summons, the dwarves gathered around, wondering what was going on.

Each one took an Aogami bar in the same reverent manner as the master. Some gasped in shock, some shouted in joy, and some even shed tears.

And when they saw the massive amount of alcohol, they let out another round of cheers.

I don't really get it, but they seem happy. Thank goodness.

Just as I was feeling relieved, the jubilant dwarves suddenly—

"Hi-ho♪"

"Hi-ho♪"

...What?

All of a sudden, they started banging on their anvils as if they were drums—

Hi-ho ♪ Hi-ho ♪

Even if the king of old is gone ♪

Even if our own bodies crumble to dust ♪

Hi-ho ♪ Hi-ho ♪

The gold we dug shall remain ♪

The steel we forged shall remain ♪

Now let us begin our work ♪

Let us stoke the fires of the forge ♪

With our hands, we shall grant eternal brilliance ♪

With magic paints, we shall give it color ♪

For our friends, we swing this hammer ♪

Hi-ho ♪ Hi-ho ♪

They...

They started singing!!!