Blacksmiths in the Ming Dynasty belonged to a special category of people, and were different from ordinary households and were called craftsmen.

Craftsmen belong to the Ministry of Works, and are divided into two categories: shift craftsmen and craftsmen. In the early Ming Dynasty, shift craftsmen must serve in the official craftsmen one or five years, with an average of three months per shift. Craftsmen will serve in the official craftsmen for ten days a month. During the Jiajing period, the Ming Dynasty government relaxed the ginseng constraints on craftsmen and stipulated that each shift craftsman receives four cents and five cents of "squad craftsmen" every year, thus abolishing the shift system. During the Wanli period, the service regulations for craftsmen were also abolished, and it was stipulated that as long as a qian of residence and craftsmen pay one cent of residence and craftsmen every month, they could be exempted from official service.

By the end of the Ming Dynasty, even craftsmen who mastered the technology of iron armor were taking orders in the market and creating various products for people. Guangzhou City had hundreds of thousands of people and countless craftsmen, so Qin Zhao was not afraid of not being able to find a blacksmith who could draw wires and make springs.

Master Han took Qin Zhao around the alley, walked into an alley with few pedestrians, and found a craftsman who was driving an iron furnace.

"Why is Han Xueheng? He's such a rare guest!"

Craftsman Han smiled and pointed at Qin Zhao and said, "Liu Datou, I'm introducing you to you today. Look at your iron kiln built in such a deep alley, and the road you walk in is bent. It's not that you are used to walking, but you can't find your kiln at all. Are you not afraid that the kiln will be hidden so deeply and there is no business?"

The man named Liu Datou smiled and said, "There is nothing I can do, I'm used to it. It's not good to have too many customers. There are only four people in the store, and there are too many customers and I can't do it."

The craftsman surnamed Han sneered when he heard this. Other blacksmiths were afraid that they would not make enough work and could not make money. Liu Datou was afraid that too many people would be unable to do things for him. He was really more angry than others.

The craftsman surnamed Han said to Qin Zhao: "Young Master Qin, this is the craftsman I said that he can make chain mail, Master Liu Datou."

Hearing Han Craftsman's words, Liu Datou was stunned and said embarrassedly: "The official of the chain mail is not a civilian, and it is a serious crime to privately hide iron armor. It is a matter of being a serious crime. It is impossible to say that it will lose its head and cannot be done!"

Qin Zhao quickly explained: "Master Liu misunderstood that we are not making chain mail, but making springs that require chain mail technology."

"spring?"

Qin Zhao nodded and said, "It is to make iron wire with fine steel and make iron wire with springs."

Liu Datou said: "What's the difficulty? Isn't it just making iron wire? Why ask me to do it! Han Xueheng can do it too."

Qin Zhao smiled and said, "I have to make a lot of springs, which cannot be done in a day or two. I heard that Craftsman Liu can make chain mail, so I naturally have some skills in building wires. I want to use Su steel as a spring. It is better to find someone else to do it."

When he heard Qin Zhao want to use Sugang as a spring, Liu Datou took a breath and said, "No matter whether you use Sugang to waste it or use Foshan's fine iron, I will receive 100 coins for the iron a day no matter how much I do it. If you are willing to pay this hundred coins, I will make a spring for you."

Qin Zhao smiled and said, "One hundred citations is only one hundred ci."

Liu Datou asked, "Is it really used Su Gang to ruin it?"

Qin Zhao nodded and said, "Just use Su Gang!"

Liu Datou spat and said, "It's good to kill talents, it's okay, it's not me who gave the materials anyway!"

Qin Zhao and Liu Datou discussed the time and agreed that in two days, Liu Datou finished all the things at hand, so he started to make the spring for Qin Zhao. Afraid that Liu Datou would not believe him, Qin Zhao first gave Liu Datou a deposit of half a tael of silver.

Su Gang was also preparing for Liu Datou Gang, and Qin Zhao would pay as much as he could.

Qin Zhao and Qin Youli were wandering around Guangzhou City, and made a few silk clothes, waiting for Liu Datou's free time in two days.

Two days later, Qin Zhao and Qin Youli found Liu Datou's blacksmith shop again.

Liu Datou had already taken out the wire drawing board and a special hammer and waited for Qin Zhao by the stove.

Qin Zhao asked him to pull the wire for himself to see first.

The iron wire drawing technology of this era is completely manual. Liu Datou put a piece of high-quality Su Gang into Rong's furnace and burned it until Su Gang was completely red and soft, and Liu Datou took out Su Gang. He pressed Su Gang to the iron plate with a hole, raised the hammer and knocked it down.

Only when I heard the loud banging sound of Dangdang, a red wire slowly emerged from the small hole on the iron plate.

An apprentice from Liu Datou quickly picked up the pliers and grabbed the wire, and carefully pulled it out slowly.

Just knocked and pulled, and after more than ten seconds, an iron wire that was dozens of centimeters long had been punched out.

Liu Datou looked at the heat, cut off the wire, and then put Su Gang into the stove to burn. When Su Gang burned it again, he put Su Gang on the hole-shaped iron plate again, and knocked it out the second wire.

Liu Datou looked up at Qin Zhao and asked, "Businessman, how about it?"

Qin Zhao smiled and said, "Liu Datou, heat him up and roll him into the shape of a spring."

Liu Datou made the case according to law.

Qin Zhao said: "Now we need to quench and medium-temperature tempering."

"Quarrying requires isothermal quenching, which not only reduces deformation, but also improves strength and toughness. The temperature of the spring entering the coolant should be controlled above 900 degrees. When the quenching is cold to 250-300 degrees, take out the air-cooling. It is best to perform another tempering after isothermal quenching, which can increase the elastic limit, and the tempering temperature is the same as the isothermal quenching temperature."

"Then heat it at a temperature of 20 degrees above the daily temperature and keep it warm for a day..."

When talking about technical problems, Qin Zhao suddenly became talkative and talked a lot all of a sudden, making Qin Youli speechless and Liu Datou confused.

Qin Youli then realized that Qin Zhao not only knew how to make large iron boxes, but also had a deep study on making springs and knew how to heat treatment. This is really amazing. How did Qin Zhao, the most stupid Qin unknowing man in my Qinjia Village, become such an omniscient talent overnight?

Could it be that the stars descended to earth and suddenly awakened?

When Qin Youli heard Qin Zhao's endless words, he made up his mind to hug Qin Zhao's thighs tightly.

And Liu Datou was completely confused.

"What nine hundred degrees, two hundred and fifty degrees? What does it mean?"

Qin Zhao said a lot, and then suddenly realized that the blacksmith around him didn't even understand Celsius. A flash of light in Qin Zhao's head, and suddenly realized that he was a little too open. This was the late Ming Dynasty, an era with extremely low technical level. Any knowledge he mastered is a precious asset, and the spring heat treatment process should be kept confidential.

Qin Zhao said seriously: "Liu Datou, it is normal for you to not understand. Don't worry about quenching and back-tempering. Just make the wire I require to make straight. Then put it bundles here, and I will use a carriage to pull it away."

Liu Datou was very happy just now, thinking that Qin Zhao was going to teach him the spring heat treatment. Unexpectedly, Qin Zhao's thoughts flashed and then retracted, as if he was preparing to keep it secret.

This is a big loss.

Liu Datou smiled angrily and knocked on the Su Gang steel block that was drawing.

"Brother Qin, why don't you let me do it for you in one go? I will never reveal it."

Qin Zhao laughed.

"Old account, we returned to the village to do the heat treatment of this spring, and we hired blacksmiths near Qinjia Village to do it. Although the blacksmiths in those villages are not very good at skill, with my guidance, there will definitely be no problem in doing simple heat treatment."

Qin Youli nodded in agreement and said, "The master is right. This Guangzhou city is intrigue. The secret craftsmanship should be assured by the people in the village. The blacksmiths hired in our village and the next village are loyal. If they dare to leak the secret, I will be the first to break their legs."
Chapter completed!