“Thank you very much. It was helpful.”
Jin thanked Duston.
“Hannah, were you watching? Your grandfather made lots of things just like that.”
“Yep, I saw. It was very different from how onii-chan does it.”
Jin patted Hannah’s head and said,
“Yeah, I on the other hand am not capable of working like that.”
Then he asked Elsa,
“So, what are your thoughts?”
Elsa replied with a slightly flushed face.
“Mm. I came to understand just how kitchen knives and other edged tools like that are normally used are made. It’ll be useful.”
“Right. Also, the final quenching and tempering is very important for iron and steel.”
Jin explained. Of course, Elsa threw back a question.
“What do you mean?”
“You see, steel is a variety of iron, and when it’s heated until it’s the color of a Citran and rapidly cooled down it becomes harder. That’s quenching.”
“Mm.”
“But if you leave it just like that then it’ll be hard and brittle and will soon break. So to make it more tenacious it has to be tempered. That can be done by warming it up to the point that droplets of water spilled on it begin skittering around, then letting it slowly cool down.”
“Mm, I understand.”
“Whether you know this or not has an effect on the quality of the Magi Craft.”
Once Jin had explained that far, Duston came nearby with a grim look on his face.
“H-hey, youngster! Who did you hear that secret from? Normally a master teaches that only when you’ve become qualified, right? Even I was taught it only when I had reached my thirties!”
He seemed to be surprised that Jin who looked like he was less than 20 years old knew this (although Jin was already 21 years old).
“Who, well, my teacher.”
“Your teacher’s generous, or maybe I should say they’re amazing…”
Duston was amazed.
“Hey, onii-chan, show us how you make a kitchen knife too.”
“Mm. I also want to see Jin-nii make one.”
Encouraged by Hannah and Elsa, Jin turned to Duston while smiling strainedly and asked,
“May I use your workshop?”
“Yeah, go ahead and show me how a Magi Craftsman works.”
Duston said and gave his permission.
Jin immediately went to where the iron ingots were.
“[Analyse]. …hmm…”
After confirming the quality of the iron, Jin called Elsa over to teach her.
“Elsa, come over here for a bit. …Listen, to examine the composition of this iron you can use [Analyse], but you won’t be able to understand substances you’re not familiar with. So knowledge is important.”
Jin said and after once again using the [Analyse] magic to confirm the composition for himself, he told Elsa to give it a try.
“Mm. [Analyse].”
It went well on the first try, but,
“…I could somehow tell what was iron. But everything else is a mess and I couldn’t tell what was what at all…”
Elsa said with a frown.
“Haha, that’s natural. Look, [Extraction] copper. [Extraction] silicon. [Extraction] sulfur. [Extraction] phosphorus. ”
Jin used [Extraction] four times on the large ingot. With it, although the amounts were small, copper, silicon, sulfur, and phosphorus were separated from it. They all were in amounts small enough to fit in the palm of your hand, but considering they were impurities it was an amount that couldn’t be disregarded.
“Look, these are the impurities. Each one of them are pure substances, so give a go at using [Analyse] on them.”
“Mm. [Analyse]. …Ah.”
“How is it?”
Elsa looked a little surprised so Jin asked. Elsa blushed and,
“I can kind of recognize copper and sulfur.”
Since they both were materials she was kind of familiar with, even Elsa became able to differentiate between them.
“Alright. Since taking too much time would probably be a bother, let’s stop today’s lesson here. Watch me do the rest.”
“Mm.”
Jin ended lecturing Elsa and resumed making the kitchen knife. Behind him it seemed like Duston’s jaw had become disconnected but he didn’t notice it. At the side, Reiko was proudly throwing out her chest.
“[Separation]. [Forming].”
Jin separated a necessary amount of iron using Craft Magic. With the next magic he changed the shape of the iron in his hand into a kitchen knife.
“Alright, let’s have the shape like this I suppose. I’d want to use [Heat Treatment] next but there’s a bit too little carbon for that, huh.”
Jin had checked it and the carbon content was about 0.5 percent. The amount of carbon was the most important component that determined the hardness when quenching, and for a kitchen knife a carbon content of 0.8~1.2 percent was suitable.
“[Carburising].”
He then decided to draw carbon from the carbon dioxide in the air and mix it with the iron. This magic could only mix the carbon with the surface, so he used the [Homogenize] Craft Magic to make the composition uniform.
He repeated this multiple times until the carbon percentage was one. That was suitable.
“Alright, Elsa, pay attention now. [Heat Treatment].”
Since he did it slowly, Elsa was able to perceive the kitchen knife Jin held instantly heating up, rapidly cooling down, then heating up once more and returning back to the normal temperature, all while observing the flow of the Magic Energy.
“Isn’t it hot?”
Elsa asked with worry as, although it was for just an instant, she had sensed the temperature grow until the iron was Citran-colored (orange).
“Yeah, it’s fine. What you perceived was simply the phase change of iron, it’s not like it really went to that temperature. That’s the good thing about Craft Magic.”
Jin said and handed the kitchen knife to Elsa. She physically felt that it was indeed not hot.
Behind them Hannah was watching with eyes sparkling, and next to her on top of having his jaw seem dislocated Duston’s eyes were so wide it seemed like they could fall out any moment now.
“Finally let’s make the blade. [Shaping]. Let’s also clean up the surface. [Finish].”
The blackish kitchen knife glittered with silver gray.
“Alright, it’s complete. Duston, do you have a handle for this? …?”
Jin said and turned, and behind him Duston was making an indescribable face.
“Hello. Anyone there, Duston?”
Jin called out to him, and gradually Duston rebooted.
“Y-yes. I was just surprised since this is the first time I’m seeing a Magi Craftsman work. B-but, just wait a minute, what did you do to the ingot!?”
He was apparently talking about the separation of impurities that Jin did.
“Well. There was a bit too much impurities mixed in so I separated them.”
“…You can do even that?…”
Duston gave an impression of slight exhaustion.
“Anyway, a handle, huh. Here’s one of the standard handles I use.”
It was a kitchen knife’s handle made out of hard wood. Since the knife Jin made was nearly the same size as Duston’s, he attached the knife to the handle and it was finished.
Gloria who had been similarly watching Jin’s way of working was likewise absentminded until now when she also rebooted.
“Ji-Jin-dono! You’re amazing! What Lithia said really wasn’t a lie! Could you please make my sword soon too!?”
The pitiable beauty showed her character.
Jin gave a nod and asked,
“Alright. So, what kind of a sword would you like?”
“The official equipment for us female knights is a short sword. A sword with a blade of 50 centimeters and a handle of about 20 centimeters would be preferable.”
These short swords were called such to contrast with the long swords used while riding a horse. It didn’t mean that the sword was particularly short
“Got it.”
Jin said and secured a necessary amount of iron from the ingot from earlier using [Separation]. Since he was familiar with Lithia’s sword he already had a rough idea about the general amount needed.
He then used [Forming] and [Carburising] followed by [Heat Treatment], [Shaping], and finally [Finish].
Additionally he applied [Hardening], completing the sword’s main body.
Elsa who had watched him work asked a question.
“Jin-nii, why did you use [Carburising] fewer times compared to earlier? And you didn’t use [Homogenize].”
“Oh, well spotted. Breaking is the worst case scenario for a sword. An ideal sword doesn’t break, bend, and cuts well. To realize this I use composite materials.”
Jin explained.
“Composite materials?”
“Yeah. To put it simply, comparatively soft iron is used in the core portions and the edge portions use hard steel. The surfaces are then hardened.”
After Jin told her that, Elsa said she understood and raised her eyes.
“If the core is soft it doesn’t fracture easily. By using [Carburising] on just the surface it becomes difficult to bend. And after hardening it cuts well.”
“You got it.”
Elsa seemed happy and slightly blushed when Jin spoke well of her.
“Y-y-y-you! T-this is the first time I’m hearing about that kind of a manufacturing method! Is it alright to thoughtlessly spread a secret like that?”
Behind them, Duston seemed agitated as he spoke.
“Eh, it’s alright. I borrowed your workshop and even used some of your iron, Duston. Ah, do you have any materials for making the sword’s sheath or the handle?”
Duston was taken aback by Jin’s calm reply and his agitation ended.
“Yeah… Missy, what a guy you brought with you.”
While speaking he pointed at a material shelf in the back.
“You can use whatever you like that’s there.”
Jin then searched the shelf.
He chose heavy leather for the sheath, bronze for the guard, and solid wood for the grip. He quickly shaped and processed these with Craft Magic too, and soon the short sword was completed.
“Gloria, I’ve had you wait for quite a while. Please take a look.”
“Uhm, thank you.”
After accepting the short sword Gloria immediately drew it and tried swinging it lightly.
“How is it? Since the weight can be adjusted a little, please don’t hold back.”
“I see. It feels like the tip is a little heavy.”
Gloria told her impressions to Jin.
“Got it. You can keep holding to it just like you were. …[Forming].”
Jin made the sword taper a little more towards the tip.
“How about now?”
Gloria tried swinging the short sword once more and,
“Mh-hm, this is good! Thank you, Jin-dono!”
She smiled with her whole face and thanked Jin.