The next morning, Liu Li squeezed into the entrance of the personnel department with a group of new workers. Everyone was tense, some clutching the hem of their clothes, some standing on tiptoe to peek inside, not daring to even breathe loudly—afraid of leaving a bad impression on the leaders and being assigned to a tiring and remote position.

Before long, the cadre in charge of recruitment arrived with several workshop directors. The first one, Director Zhao of the machine tool workshop, was in his fifties. His voice was like a gong, immediately drowning out the murmurs in the room: "Quiet down! Those whose names are called, follow me. I'll call one, and you step forward!"

He held a list in his hand and read it quickly and loudly: "Wang Qiang! With Master Li!" "Zhang Xiaomei! With Master Zhang!"... When he finished reading, he glanced around and his gaze fell on Liu Li: "Liu Li! You're with Wang Jianguo, Master Wang!"

As soon as these words were spoken, several people in the front row subconsciously shrank back, their furtive glances at Liu Li revealing a mixture of sympathy and barely concealed relief—as if they had dodged a major problem. The words Zhang Shulan had muttered in the dormitory the night before suddenly reached Liu Li's ears: "Whatever you do, don't be assigned to Wang Jianguo's group! He can make people cry!"

Liu Li's heart skipped a beat, thinking to herself, "What I feared most has come to pass," but she still had to smile and quickly walked up to Master Wang, her voice crisp and clear: "Hello, Master! My name is Liu Li. Please take good care of me in the future!"

Master Wang grunted in response, waved his hand, and turned to walk back to the workshop. Liu Li quickly followed, her steps a little heavy, her heart pounding.

Upon entering the machine tool workshop, Liu Li was stunned by the scene before her—overhead cranes rumbled overhead, shapers clattered, and the sound of rows of lathes turning made her feet numb. The smell of machine oil mixed with metal shavings filled her nostrils, and the deafening roar of machines filled her ears. She had barely paused, thinking, "I'll be working here from now on," when Master Wang's voice boomed down, without a hint of politeness: "I don't care how well you did on your written test. Once you're here, you have to follow my rules. Three: First, follow instructions; don't touch machines you're not allowed to touch. Second, be able to endure hardship; don't complain even when you're tired. Third, don't let your mind wander while working; your fingers and eyes must be engaged. Safety first. Can you do those three things?"

Liu Li quickly straightened her back and raised her voice high: "I can do it, Master!"

"Come with me." Wang Jianguo turned and walked to the corner of the workshop, where there were several fitter workbenches and a metal tool cabinet next to them, which was the territory of the fitter group under his management.

Liu Li, clutching her notebook filled with notes, followed her master to learn the basics. In the morning, they learned about the tools. Master Wang opened the tool cabinet and laid out wrenches, screwdrivers, and hammers all over the table. Even the hammers were divided into round-headed and tenon-headed types, and the files were arranged in a row according to the coarseness and shape of the teeth—flat files, square files, triangular files—making Liu Li's eyes dazzled.

"Tools are a worker's gun. If you don't know them all or are not good at using them, you'll be sent to your death on the 'battlefield.'" Master Wang picked up a pair of needle-nose pliers. "These are for clamping thin wires and bending small parts. You can't use them as wrenches to tighten screws, they'll break easily." He explained each tool one by one, and finally mixed them together. "I'll close my eyes and feel around, and I'll tell you which one I can find. The purpose and precautions must be correct. If you get one wrong, you have to start all over again."

Liu Li was extremely nervous, afraid of saying something wrong and being scolded by her master. Her hands were trembling as she touched the surface with her eyes closed. When she touched a semi-circular file, she thought for a moment and quickly said, "This is a semi-circular file. It's for filing curved surfaces, like the grooves on a shaft. When you use it, you have to follow the curve..." Master Wang didn't say anything, just nodded, and she breathed a sigh of relief.

In the afternoon, while identifying materials, Master Wang rummaged through the scrap bin and found several pieces of scrap metal, some black, some yellow, and some silver-white. He picked up a black piece and a silver-gray piece, and banged them together. "Listen to the sound! A dull sound is cast iron, a crisp and shiny sound is steel." Then he picked up the yellow piece. "This is brass. It's soft, has a bright color, and can be used to make small parts." He made Liu Li repeatedly weigh, tap, and examine them until she could distinguish these commonly used materials at a glance.

By the end of the day, Liu Li's mind was full of memorization, and her hands were sore. It wasn't until a few minutes before the end of the workday that she finally managed to memorize everything her mentor had taught her, without daring to slack off for even a moment.

The next day, as soon as she arrived at work, Master Wang tossed her a piece of scrap steel—about eight inches long and three fingers wide, with a pitted surface and covered in oxide scale. He then handed her a medium-toothed flat file: "Today, file this side flat and smooth. Measure it with a square; it should be opaque. The flatness error cannot exceed three micrometers."

Liu Li was stunned—three strands! That's as thin as a single hair! But she didn't dare complain. She took the steel and file, recalled the cross-file technique her master had taught her, steadied herself, gripped the file tightly with both hands, and began to push it down.

"Wrong posture! Use your waist and abdomen, don't just use your arms!" Master Wang's stern voice suddenly rang out behind her. Liu Li quickly adjusted her posture, lowering her waist slightly.

"Pace! Don't go fast and slow all the time, like you haven't eaten!"

"Use more force evenly! Look here, you've filed it too deep!"

All morning, the roar of the machines in the workshop became background noise. All Liu Li could hear was her own panting, the "shh" of the file grinding against the steel, and her master's occasional corrections. Sweat streamed down her face, dripping onto the steel with a "thud" and disappearing. Her palms were red from being rubbed by the file handle, and later blisters formed. When the blisters broke and blistered, the blood seeped out, rubbing against the wooden handle, causing both pain and itching, but she didn't dare stop.

At lunchtime in the cafeteria, Zhang Shulan came over, pried open her hand, and frowned deeply: "My goodness! Is Master Wang treating you like a lump of iron? On our first day in the workshop, the senior workers made us clean the machine tools and watch others work. Unlike you, you're suffering like this!"

Liu Li poked at the cabbage and potatoes in her lunchbox with her chopsticks and smiled, "A strict teacher produces outstanding students, right?" But when she saw that piece of steel in the afternoon, she was still a little scared—her arm was still so sore that she couldn't lift it.

Over the next few days, the task remained the same: filing flat surfaces. However, the requirements became increasingly stringent, decreasing from three lines to two. Liu Li's palms developed calluses, and scabs would fall off and regrow. When she returned to the dormitory at night, she was so exhausted that she didn't even have the strength to speak. Lying down on the bed, her arms felt like they didn't belong to her. Her roommates, seeing her like this, were secretly astonished and even more grateful that they hadn't been assigned to Master Wang's work.

As time went by, Liu Li gradually figured it out—she could feel where the file was too high or too low by its texture; the rhythm of her filing became steady, and the cutting marks became more and more even. On the afternoon of the fifth day, she measured with a square and moved it along the edge; the tiny gap was almost gone!

She couldn't help but lift the steel piece up to the light. The surface was so bright it reflected a faint shadow. A warm feeling welled up inside her, and all the fatigue and frustration of the past few days vanished. Before she could finish feeling happy, Master Wang came over. Still expressionless, he picked up the steel piece, first checking it with a square, then took out a standard flat plate, coated it with red lead powder, and ground the steel piece on it. He examined the contact spots—dense, evenly distributed.

He put down the steel, his gaze finally settling on Liu Li's face for the first time. Her cold, hard expression seemed to have softened; she wasn't so sharp anymore. "Tomorrow, practice grinding the drill bit." With that one sentence, he turned and went back to his own work.

Liu Li's heart skipped a beat—grinding drill bits wasn't just about brute force; you needed to understand cutting principles, it was a real skill to learn! She knew she had finally barely passed the first hurdle—this incredibly boring yet most solid test. But grinding drill bits required even more keen eyesight and experience; what challenges would she face next?