Studying at Western University starts with a knife-forging competition

The next step is overall quenching.

He adjusted the angle at which the blade entered the water. Instead of simply letting the blade glide across the surface, he inserted the entire blade—from the tip to the base of the handle, from the edge to the back—into the water in a smooth, angled arc.

"Hiss—gurgle—"

Large plumes of steam billowed from the quenching tank, and the water boiled violently. The rest of the blade blank underwent martensitic transformation at a relatively gentle cooling rate. The hardness of the back and body of the blade was lower than that of the cutting edge, but its toughness was much higher.

The internal stress distribution of the entire knife exhibits a subtle step-like change—from the ultra-high hardness of the cutting edge, it gradually decreases through the transition zone, and by the back of the knife, it has reached the optimal balance point between hardness and toughness.

After the knife blank remained in the water for a moment, Lin Yuan took it out.

Without pausing, he directly placed the quenched blade blank into the sand trough next to the forge—a shallow iron box filled with dry fine sand, originally used for slowly annealing blade blanks. He buried the blade blank in the sand, leaving only the base of the handle exposed, and then turned on the propane torch to heat the surface of the sand layer evenly.

When the sand temperature reached around 180 degrees Celsius, he turned off the spray gun, allowing the tool blank to complete the tempering process in the residual heat. During the low-temperature tempering, the quenched martensite partially decomposes, stress is released, and the hardness drops slightly from its peak brittleness to the ideal equilibrium point for the tool.

This step cannot be omitted—the steel billet that has just undergone martensitic quenching has extremely high internal stress and is very brittle. If it is not tempered in time, it may spontaneously crack during the cooling process.

While a simple tempering process using a sand trough may not be as precise as a professional tempering furnace, it is aided by the [Internal Vision] skill, which allows the user to perceive every detail of the changes in the internal structure of the blank, making the effect more direct than a thermometer.

Twenty minutes later, the tempering was complete.

Lin Yuan removed the knife blank from the sand and let it cool naturally to room temperature in the air. He straightened up, let out a long breath, and wiped the sweat from his forehead with his sleeve.

On the judges' panel, J. Nelson leaned forward. He rested one hand on the edge of the table, his gaze never leaving Lin Yuan's quenching tank.

It wasn't the kind of cursory glance, but the kind of intense scrutiny that comes from someone who has stood in front of the forging table for decades, instinctively wanting to see every detail when witnessing an unexpected operation.

David Baker crossed his arms and slowly leaned back in his chair. The two men exchanged a glance.

J. Nelson took off his glasses, wiped the lenses with the hem of his shirt, put them back on, and then slightly raised his chin toward Lin Yuan's workstation, his voice carrying an interest that was moved by the craftsmanship itself: "Partial quenching, alternating between the two sides, and then immersing the whole thing in water. He pushed the oil tank aside and didn't even touch it."

"Damascus steel is either water-quenched, or it doesn't know what it's doing, or it knows too much about what it's doing." David Baker's gaze swept over the cooling blade blank. "So far, it hasn't cracked."

"No cracks, no warping. Even I would find it difficult to do this." J. Nelson leaned back in his chair, his hands clasped in front of his stomach. "This kid's hands are incredibly steady."

After cooling, Lin Yuan clamped the blade blank in front of the belt sander and began rough grinding.

Starting with 400 grit, then 600, 800, 1200, and 2000 grit, the grit level remains constant. After each grinding step, the blade surface is run along with the fingertip to check for flatness, and after each grinding step, it is soaked in water to cool down.

The speed of the belt sander is always controlled within a range that will not cause localized annealing of the cutting edge.

After the coarse grinding was completed, he picked up the ferric chloride solution for pickling.

The pickling time depends on the number of layers in the billet and the desired pattern contrast. For a nearly three-thousand-layer cloud-patterned steel billet with extremely thin interlayer interfaces, prolonged pickling will cause excessive corrosion of the darker layers, resulting in a decrease in pattern contrast.

He kept the pickling time shorter than usual, then quickly rinsed it with clean water, and then neutralized the remaining acid with baking soda water.

The moment the pickled blade blank was rinsed clean and dried, the camera lights on the workshop ceiling illuminated the blade.

The entire workshop was silent for two seconds.

On the blade, the cloud patterns seemed to come alive. They were not the neat parallel patterns of ordinary Damascus steel, nor were they random wavy patterns, but rather layer upon layer, piece by piece, independent yet echoing cloud-like patterns.

The edges of the pattern are not hard boundaries, but rather have a soft transition—there is an extremely fine gradient between the dark and light layers, making the cloud pattern look not like a pattern engraved on the blade, but like slowly flowing clouds coming from inside the blade.

The nearly three thousand layers of folding and forging stretched the dark color of 1084 and the light color of 15N20 to a thickness that is almost indistinguishable to the naked eye, but they did not become a blurry mess.

The basic framework of the cloud pattern is broken down and reassembled during folding. Carbon migration between each layer creates a special contrast at the interface, giving the pattern a flowing three-dimensional feel when it rotates under light.

It was as if clouds were truly surging, swirling, and flowing within the blade.

The cloud patterns on both sides of the blade unfold symmetrically from the tip to the root. The symmetrical pattern on both sides gives the dagger a unique visual effect when it is turned over—the patterns on the front and back are not mirror images, but rather resemble the same cloud layer seen from different angles.

There was a moment of silence on the judges' panel.

J. Nelson rested his hands on the table, leaned forward, and stared at the dagger for a long time. Then he took off his glasses, rubbed the bridge of his nose with his fingertips, and put them back on. His lips moved as if he wanted to say something, but he swallowed the words back.

Finally, he simply gestured with his chin toward the dagger and said in a rare, somewhat solemn tone, "You can go and see for yourselves."

David Baker leaned forward slightly, his buttocks already half an inch off the chair. He tapped his fingers lightly twice on the edge of the table, as if making a decision. Then he sat back down.

He didn't stand up. There were only a few steps between the judges' table and the workstations, but those few steps meant a lot during the recording—judges personally inspecting a knife was something that usually only happened during the testing phase in the rules of the "Knife Forging Competition."

The first round wasn't over yet, and he couldn't break the rule. But he didn't take his eyes off the knife either.

He leaned back in his chair, looking over the judges' table toward Lin Yuan's workstation, his arms crossed over his chest, his fingers unconsciously pinching his chin.

His gaze swept across the blade from tip to base, from the edge to the back, clearly seeing the flowing cloud-like patterns even from several meters away. Then he slowly leaned back in his chair.

"The pattern hasn't blurred even after reaching this level of layering; it's more than just good craftsmanship." He pushed up his glasses, deliberately maintaining the calm demeanor expected of a judge, but speaking a few decibels slower than usual. "This is something that can only be achieved when one has a deep, ingrained understanding of the materials."

But the third judge, Doug Macheda, sitting on the other side of the judging panel, couldn't sit still any longer.

Doug Macheda, a former Navy SEAL, worked as a knife tester for twenty years after retiring. He was known as "Dog" because of his ruthless and merciless approach to testing knives.

In this show, his job is to push each knife to its limit and then tell the audience in front of the camera whether the knife is usable or not.

He wasn't interested in the patterns. He wasn't particularly interested in the forging process either. He was only interested in one thing: whether the knife was sharp enough, sturdy enough, and whether it could survive a violent test.

But at that moment, he was staring at the dagger.

It's not about looking at the pattern, it's about looking at the blade line. That blade line, extending from the tip to the hilt, gleams under the camera light with a very subtle sheen that only seasoned knife enthusiasts can discern—the unique luster of a high-hardness blade after water quenching.

He had seen this luster before. Not often, but each time he saw it, it meant that a knife capable of turning the testing process upside down had appeared.

Doug reached out and pressed the intercom on the table.

"Mark." His voice was rough and short.

Production assistant Mark jogged over from the edge of the workshop, bent down, and approached the judges' panel. "Doug, what's wrong?"

What was originally planned for the first round of testing?

Mark opened the whiteboard. "Standard hunting knife test—cutting rope, shaving wood, splitting cow bone. Fifteen minutes."

"Change it," Doug said.

Mark paused for a moment. "...Change it?"

"Splitting cow bones?" Doug gestured with his chin toward Lin Yuan's workstation. "Using cow bones to test that knife is a waste of a good knife and a waste of cow bones."

He leaned back in his chair, the muscles in his jaw twitching as if he were chewing on something unseen. Then he grinned, a smile devoid of malice, but tinged with an excitement that instantly put all the production staff on edge.

"Prepare several more rolls of hemp rope. Thick ones. And some soaked canvas. And that bundle of dried bamboo planks that's been pressed for three years—yes, the one we prepared for the champions the season before last." He paused. "Replace the cow bones for chopping with larger ones. I'm afraid that knife won't withstand the standard test."

Mark opened his mouth and glanced at J. Nelson. J. Nelson did not object, but his gaze remained fixed on Lin Yuan's workstation, and the corner of his mouth twitched slightly.

Then Mark's gaze shifted to David Baker, who nodded slightly, his expression unchanged, but the rhythm of his fingers tapping on the edge of the table had stopped. That was his habitual gesture when making decisions.

"Go and get ready," David Baker said.