The mold filled with molten iron was moved out of the Zhuanghu factory, steaming hot.

"Fengzi, such a big arrow, how can anyone move it, even if you pick it up, you can't shoot it!" Cheng Chumo looked at the mold and said to Qin Feng.

"It's not for people, it's for a crossbow to shoot!" Qin Feng didn't raise his head, and said silently towards Cheng.

"The car crossbow doesn't need to be made of steel, it's a lot of money!" Cheng was puzzled, steel was too expensive in this era. A pure steel arrow can buy several bundles of iron arrows.

"This arrow is called an armor-piercing arrow, and if you shoot it, even a five-layer iron armor can shoot through it." Qin Feng replied.

"Shhh Cheng Chumo gasped, five layers of iron armor can be shot through, whoever goes to the battlefield will wear five layers of iron armor.

"It'll be ready to use when it's cold in a while!" Qin Feng said.

"I'll go back and pull a cart of crossbows right now, wait for me!" After Cheng Chumo finished speaking, he had to hurriedly run to pull the crossbow, these military supplies are in Chang'an, there is no here, you have to go back to pull it.

"Wait, I didn't say I didn't have a crossbow, go, pull the crossbow I made two days ago!" Qin Feng said to a craftsman on the side.

"It's the young master!"

After a while, several craftsmen pushed out a crossbow more than one meter wide and three meters long from a tent, this is the crossbow that Qin Feng had seen in the ancient tourist city in his previous life, so it was also the reason why Qin Feng built this armor-piercing arrow in the first place.

Half an hour later, the mold was opened, and the armor-piercing arrow in Qin Feng's mouth was nothing special, at least in Cheng Chumo's eyes. The only thing that made Cheng Chumo feel a little chilly was the three-edged arrow, if this arrow was slightly polished, it would definitely be a sharp weapon for killing.

"How? Looks okay? Qin Feng picked up the arrow and asked silently towards Cheng.

"You have to try it to find out! If you weren't as godly as you said, I'm afraid Your Majesty wouldn't agree to you casting arrows like this! Cheng Chumo still didn't believe that this arrow was as powerful as Qin Feng said!

"Then try!" Qin Feng then instructed the craftsman to load these arrows onto the crossbow, a total of eight.

"Fengzi, don't polish? This blade has not been opened, and it is said that it wants to break the armor? Cheng Chumo was suspicious.

"Don't worry, try first! Here, shoot me at that wall! "Qin Feng commanded this craftsman.

"Yes!" The craftsman turned around and aimed at the place where Qin Feng said.

"Launch!" With Qin Feng's order, the craftsman opened the mechanism of the crossbow, and then saw eight arrows flying towards the location Qin Feng said, and then there were several loud bangs!

"Boom!" There were eight hollows on the wall that Qin Feng had just pointed out with a diameter of more than ten centimeters. And the arrows have flown out of the wall.

"I'll rub!" It was not only Qin Feng and Cheng Chumo who were shocked, but the craftsmen and other people who were watching here were all stunned, you know, this arrow is still unbladed, it has not been polished, and it is shooting at the wall, not people, if the arrow is polished and bladed, I am afraid that it will really be like what Qin Feng said, even the five-layer chain mail will not be able to stop this arrow.

"You guys, go pick up the arrows!" Qin Feng instructed a few craftsmen.

"Yes, young master!"

"How's it going, Chu Mo, this arrow is okay?" Qin Feng smiled and asked silently.

"It's just too good!" Cheng Chumo said excitedly.

"Try it again when you're done!" Qin Feng took the arrow he picked up, it seemed that the steel had been smelted, if it was pig iron, I was afraid that it would break directly, and wrought iron, it would bend, but this arrow did not leave any traces, it was still the same as it had just been produced.

"Fengzi, what is refined this time is steel, right?" Cheng Chumo walked up to Qin Feng and asked quietly.

Qin Feng didn't speak, and glanced at Cheng Chumo, of course, so many days of experiments are not in vain, what is practiced in the blast furnace is pig iron, because iron ore is neutralized with coke, and the carbon content in it is high, but the open hearth used now, the pig iron will not be removed from the fuel after heating, and the matter is that he melts at high temperatures, and after adding some source materials for neutralization, the carbon components are discharged in large quantities, so steel is formed. After many experiments, it finally succeeded. Qin Feng's face was relaxed. In the future, according to this ratio, the source material can be added to make steel.

"Chu Mo, you take care of this place, I will go back to the palace now and report to Your Majesty!" Qin Feng said silently towards Cheng.

"Okay, there you go! I'm here for you! Cheng Chumo replied.

"Huaiyu and Li Zhen will come back in a while, let them not go out again, there should be a holy decree issued tomorrow!" Qin Feng said silently towards Cheng. This steel has also been practiced, I am afraid that the next step is to order mass production, Li Shimin knows that he will not take care of this stall, so the three of them will definitely be the heads of the iron factory. Otherwise, I wouldn't have told them to come with me.

Calling a team of guards, putting on an ox cart, Qin Feng took a few unpolished armor-piercing swords, hummed a small song, and led a team of 100 people towards Chang'an. But the last time Qin Feng came, he slept all the way to the mine, and he didn't know how far Chang'an was in the mine, but when he arrived in Chang'an, Chang'an was curfew, and Qin Feng had no choice but to return to Qinzhuang to stay for one night.

On the second day, Qin Feng got up early, and after breakfast, he led people to Chang'an, this matter has been a whole month, it should be over, and he still owes Princess Changle a hundred amounts of rickshaws.

In the palace, as soon as Li Shimin returned to the Taiji Hall after the morning court, Gonggong Li came in and reported that Qin Feng asked to see him. As soon as Li Shimin heard this, he guessed that the steel had been trained, otherwise Qin Feng would not have come back, and said happily to Gonggong Li.

"Bring him in!"

A moment later, Qin Feng was brought into the main hall by Gonggong Li.

"Minister Qin Feng greets Your Majesty!"

"The steel is out?" Li Shimin couldn't wait to ask Qin Feng.

"Back to Your Majesty, it's been refined." Qin Feng bowed and replied.

Li Shimin looked left and right, but he didn't find anything on Qin Feng's body, and hurriedly asked, "You didn't bring back a piece?" ”

Qin Feng still thought that there was something on his body, it turned out that Li Shimin wanted to see things, and said to Li Shimin: "The minister brought it back, but the thing that the minister brought back was too much like a weapon, and it was taken away by the guards!" ”

"Go see what's going on!" Li Shimin said to Li Gonggong.

"Yes!" Gonggong Li was ordered to go out to find the guards to get something. After a while, he brought back the armor-piercing arrow brought by Qin Feng.

"Is this an arrow?" Li Shimin glanced at Qin Feng and asked, I don't know how Qin Feng brought this thing back.

"Your Majesty, this thing is an armor-piercing arrow, the steel is directly poured and formed, and it has not yet been opened, it is an arrow on the crossbow! This is also done to test the hardness of steel! Qin Feng said to Li Shimin.

"It's called an armor-piercing arrow? Why? Li Shimin picked one up and looked at it in his hand, asking at Qin Feng.

"If you open the front, you can break the iron armor, and the five layers can't stop it!" Qin Feng replied.

"What? So powerful? Is there an experiment? Qin Feng's good news came one after another, which made Li Shimin a little overwhelmed!

"After the experiment, the unopened armor-piercing arrow can shoot through the wall three feet behind, if the blade is opened, the five-layer iron armor can't stop it!" Qin Feng replied with a smile.

"I'm going to try it! Go, get my bow, and get some of the craftsmen for me, and polish all these arrows! Li Shimin instructed Gonggong Li.