Chapter 249 A peerless talent wasted. When Su Tang and Chen Xiaocao pushed open the dilapidated wooden door of the gun repair workshop, a strong smell of gun oil mixed with the smell of rust rushed out.

Old Sun was sitting on his small stool, puffing on his pipe, the smoke obscuring his wrinkled face.

Cigarette butts were scattered all over the ground.

Clearly, he knew everything that had just happened on the playground.

Hearing the door open, Old Man Sun looked up and saw Su Tang. A glimmer of light flashed in his cloudy eyes, but it quickly dimmed again.

"Su Meizi, you... why are you back?" He tapped his pipe on the sole of his shoe and asked in a hoarse voice.

"Master Sun, I'm back to use the lathe a little longer," Su Tang said calmly, as if the scene on the playground that had just crushed everyone's confidence had no effect on her whatsoever.

"Still...still using that firing pin?" Old Sun was stunned. "Why don't you go and get some rest? Tomorrow you're going to compete against Battalion Two."

Su Tang hummed in agreement, then walked to the C616A lathe, picked up the half-finished prototyping of the firing pin, and carefully measured its dimensions with calipers.

Her movements remained steady and focused, as if all the noise and despair of the outside world were isolated from her.

"Master Sun," Su Tang asked without looking up, "where is the oil bath for quenching? And the electric furnace for tempering?"

Seeing her stubbornness, Old Man Sun felt both anxious and angry, and finally let out a long sigh.

"Alright, you're quite stubborn, girl." He stood up, brushed the ash off his pants, and said, "Come with me."

He led Su Tang to a corner of the workshop, where there was a metal cabinet about half a person's height. When it was opened, a wave of heat rushed out. It was a small box-type electric resistance furnace, which was used for tempering. Next to it on the ground was an iron drum filled with black machine oil.

"The oil's here, the stove's over there. Do whatever you want with it," Old Sun said irritably, then sat back down on his little stool and started puffing on his cigarette in silence.

Su Tang didn't say anything more. She put on thick work gloves, used pliers to clamp the small firing pin prototype, and turned on the electric furnace.

She placed the parts into the furnace, set the temperature, and then waited quietly.

Time passed by, second by second.

In the workshop, only the faint hum of the electric furnace and the smacking sound of old man Sun smoking remained.

When the parts inside the furnace were burned to a bright, cherry-red color, Su Tang's eyes instantly sharpened.

Now!

She yanked open the furnace door, precisely clamped the red-hot part with tongs, and without the slightest hesitation, plunged it into the oil tank beside her with lightning speed.

"Sizzle—!"

A piercing shriek followed, accompanied by a thick plume of white smoke shooting into the sky.

Quenching!

This is to give the steel extremely high hardness!

Old Sun was startled by the sudden commotion, and almost dropped his pipe. He turned around abruptly, staring at Su Tang's movements.

Su Tang didn't stop. She took the quenched parts out of the oil, and the firing pin had turned pitch black. Instead of proceeding to the next step, she carefully sanded the head of the firing pin with a piece of sandpaper until the shiny metal was revealed.

Old Sun's pupils contracted.

An expert! This is definitely an expert!

This is so that during the subsequent tempering process, the temperature and time of tempering can be accurately determined by observing the change in the metal color!

Sure enough, Su Tang put the parts into the electric furnace again. This time, she didn't close the furnace door, and her eyes were fixed on the polished metal surface like an eagle's.

Pale yellow... dark yellow... brown... purple...

Finally, when the bright color turned into a uniform and deep blue, Su Tang took action again, removed the part, and threw it onto the asbestos board, letting it cool naturally in the air.

Low-temperature tempering!

Old Sun could no longer sit still. He threw away his pipe, rushed over, and stared intently at the now-cooled firing pin.