Su Yuan nodded after listening, looking at the professional stone, if you want to do a good job, you must first sharpen your tools, since there are better ones, you don't need to use them in vain.

Take out the tools, fix the sword embryo, take a deep breath, stare at the sword body, and prepare to open the sword spine. Feel the direction of the golden light flowing water, and slowly follow the gradual force.

Xu Kui and Yanagi Emi didn't dare to breathe, staring at Su Yuan's every move, once, twice, three times, five times, ten times......

I don't know how long it took, Su Yuan looked at the golden light that was becoming more and more dazzling in front of him, and he had already reached the tip of the sword, and he was only one step away from the door.

"It's done!"

Following the last stroke, there was a clear sound in my ears, and the golden light skyrocketed, which was extremely dazzling. All the light seemed to have found a breakthrough, and instantly poured into the tip of the sword, as if it had opened the second vein of Ren Du and was reborn from the cocoon.

Su Yuan stood up, his eyes were a little sore, and he was finally one step closer to success, and he was in a good mood. Give the sword to the two curious babies, wash your face and rest for a while.

"It's ......"

In the eyes of Xu Kui and Yanagi Emi, the sword embryo that was originally as clear as water seemed to be steaming, exuding a breathtaking momentum, and soon calmed down again. Like a tiger in the mountains, dormant, waiting for a thunderous blow.

"Good sword!"

The two of them were shocked, they had never seen an unpolished sword embryo so breathtaking!

Su Yuan took back the sword embryo, gently touched the sword body with his hand, took out the stone, dipped it in cold spring water, and began to polish it. Sharpening the sword is like grinding the heart, and the fingers keep feeling the subtle changes of the blade, following the flowing lines of the golden light, taking off the greenness, removing the false and retaining the true.

Xu Kui and Yanagi Emi sat quietly next to them, carefully experiencing Su Yuan's movements, especially Yanagi Emi, the grinding technique is not a secret in the island country, especially the overall polishing, and even his own son may not be qualified to inherit it.

Polishing is even more familiar to Xu Kui, I don't know how many Longquan swords have been polished by myself, looking at Su Yuan's maverick technique, theoretically speaking, different sharpening directions, the sharpening effect obtained is very different.

The sharpness and strength of the blade are the highest, if the lines are parallel but not perpendicular to the edge, the second is the worst if the lines are parallel but not perpendicular to the edge, and the effect is the worst if there are interlaced patterns on the bevel lines.

If he chooses, he will recommend the oblique edge grinding method, which is more convenient to grind than the longitudinal edge grinding method, and the second is that the grinding area is wider and more efficient, and the sharpened blade is sharper.

The operating force of each grinding process is from small to large, then the holding force, and then gradually decreasing. This is because at the beginning, the stone has a small area to the cutting edge, and it is operated with a small amount of force to prevent scratching the cutting edge.

As the sharpening progresses, the area where the grinding stone fits the blade increases, and the strength should also increase. When the sharp area is about to appear, the force should be reduced to prevent the stone from scratching the cutting edge, showing burrs and reducing the sharpening marks in advance.

Polished to a certain extent, raise the sword to observe the light, if the blade can see an obvious white line, it means that the blade is still relatively thick, these parts with white lines should be focused on grinding, after grinding sharp, the blade line is almost invisible.

Su Yuan put down the sword embryo, gently wiped it clean with water, and explained: "In my opinion, the reason why the sword is sharp is mainly determined by five factors. The smaller the blade angle, the sharper the blade, the lower the cutting resistance, and the higher the sharpness, which is the most important key to the sharpness. ”

The two of them were shocked, and they were engrossed in listening to the master's words and deeds, especially Emi Yagyu, who was excited, even if she was the eldest lady of the Yagyu family, it was a great honor to be in the island country.

"The second is that the smaller the cutting edge radius, the lower the cutting pressure, and naturally the sharper it will be. If the direction of the cutting pattern is the same as the cutting direction, it is easier to cut in, so it is best to have a longitudinal cutting pattern that is parallel to each other and perpendicular to the cutting edge. ”

Su Yuan experienced it while speaking, it was also a rare experience for him to combine theory with practice, with the assistance of the Five Elements Technique and the Xiangjian Master, he knew all the details in his chest, and he was naturally at ease.

"Finally, there is the micro-aliasing of the edge of the blade, which also helps to improve sharpness. When the tooth direction is consistent with the cutting direction, the sharpest the cutting edge, the smaller the cutting pressure. ”

"It's about to be polished the tip of the sword!" Xu Kui stared at Su Yuan's hands, the tip of the sword was the most important thing for polishing, and it was also the most difficult process.

I saw Su Yuan put the tip of the sword in the upper left corner, at a 45-degree angle with the stone. As you sharpen the left blade, press your thumb against the body and hold the handle with the other four fingers.

When sharpening the right blade, press the thumb on the position of the anti-slip groove on the back of the knife, press the index finger on the blade, and hold the other three fingers. This position makes it easier to fix the sharpening angle of the sword.

The reason why the knife is held with one hand is because when using both hands, there are two forces acting on the sword, and the force is unbalanced, resulting in an uneven surface of the blade, which is prone to convex surfaces.

Su Yuan was engrossed, the tip of the sword was the key position, and there could not be the slightest sloppiness. Take a deep breath and press your hands evenly, not lightly. If it feels smooth, the plane of the blade is already attached to the stone, and the effect is best at this time.

If it feels astringent, it means that the blade is only partially polished, and you need to stop and readjust the grinding angle, the best thing to do is to remember the distance between the back of the knife and the grinding tool, and then slowly advance while sharpening, and retreat the blade until you reach each part of the blade.

"Pay attention to the master's ring finger!"

Xu Kui quickly found the doorway and reminded Yanagi Emi next to him in a low voice: "Although the cooperation of thumb and ring finger is the most suitable for high-precision manual work, such as motorcycle throttle control, opening the safe, holding a baseball bat and other work with high precision requirements, the participation of the ring finger is indispensable." ”

"You pay attention to the master's movements, mainly the horizontal swing of the forearm, when the thumb and ring finger are naturally matched, the position of the stone is just on the extension line of the forearm, and the horizontal grinding should control the up and down displacement of the action to a minimum!"

"In this way, we can try to achieve the final plane, not the arc surface, and you see that the index finger should be suspended, not on the oil stone, and you can feel the feeling of the sword body feedback with your heart, prioritize and keep your heart. ”

Su Yuan breathed a long sigh of relief, and finally completed the first overall polishing, heard Xu Kui's analysis, and said with a smile: "That's roughly right, but don't ignore the role of the little finger, basically rough grinding: light → light→ heavy→ light → light." Medium grinding: micro→ light → micro. Fine grinding: very small→ very → very small. ”

Xu Kui and Emi Yanagi quickly stood up, bowed deeply to express their gratitude, and passed on a true sentence and a fake transmission of 100,000 books. One sentence points to the true meaning of sword grinding, so that the two of them will benefit for life.

"Is this a ......?"

Xu Kui took the sword embryo, looked at the effect of the first polishing, and was suddenly shocked, and said incredulously: "Dragon scale pattern!"

Emi Yanagi hurriedly stepped forward, staring at the strange texture that faintly appeared on the blade of the sword that was as clear as water, a thought flashed through her mind, and she blurted out: "Lu Mo knife pattern...... Shaped like a dragon...... Known as dragon scales in history!"

Cao Pi's "Classics" contains that when Pi was the crown prince, he ordered the national industry to refine three swords, three swords, two daggers, and one Lumo knife, all of which were named because of their posture.

The sword color is like a rainbow, the sword is like a spirit turtle is called Lingbao, and the sword is like Danlu is called Hanzhang.

He also made a hundred Lumo knives, three feet and two inches long, like a dragon, and the name was dragon scales.