After eleven o'clock in the evening, Zhang Lingling was having a "sleeper meeting" with her roommate.

Zhang Lingling: "Xiaohua, your boyfriend's nose is so big, you are so happy." ”

"Hee-hee-hee!" ×6

Xiaohua: "It's okay. Li Siyuan's hooked nose looks pretty good. ”

"Hee-hee-hee!" ×6

Zhang Lingling: "Yes, I haven't experienced it yet. ”

Most people don't know that the girls' dormitories are bigger than the boys' dormitories.

Zhang Lingling, who was falling into a fantasy, suddenly received a WeChat friend application.

[I love you in this life and apply to add you as a friend, please verify...]

Who is this, the name is so sassy.

Zhang Lingling secretly thought, I didn't tell anyone else about my WeChat account except for Jiang Hao's friends today?

Isn't his name "Bright Moon on the River"?

Wait, it won't be...

Jiang Hao used his trumpet to add my WeChat?

Zhang Lingling, who has a high degree of confidence in her beauty, feels that this is possible.

Did he see that I already had a boyfriend, and he was embarrassed to talk to me in a large number, so he changed to a small one to approach me?

Hey, my damn charm.

I didn't expect that boy to look cold, but he was still so sullen in his heart.

Agree to his friend application and see what he wants to do.

She reached out and clicked on a [Verified]

On the other side, a scream pierced the night sky from the boys' dormitory 404.

"She's approved my friend application!"

Jiang Hao covered his head in the quilt and shook his head helplessly.

Bad fate!

...

The next day, Jiang Hao was going to find Wang Chaoyang to go to the training workshop warehouse to find materials.

The shaft used in their robotic arm is to be changed to 360° degrees of freedom rotation, and a combination of gears and bearings will be used.

In this way, the function of both transmission and rotation can be satisfied.

This kind of composite parts need high hardness, good toughness, high bearing capacity, high wear resistance, and ordinary iron can hardly be satisfied.

"What are your weight requirements?" Wang Chaoyang asked.

"We designed the load limit to be 50kg," Jiang Hao said.

"Hmm... I'm afraid that ordinary cast iron materials will not work. Our school has not processed special parts, and there are no suitable materials in the warehouse. ”

"What then?"

"You can go to the hardware market."

"Mr. Wang, are you free? Shall we be together? ”

"Teacher... Something. ”

Jiang Hao said bluntly: "The main thing is that the purchase of this material should be paid for by the school..."

His living expenses are not rich in the first place, and if the materials are very expensive, then he can only eat soil this month.

Wang Chaoyang thought for a while and said, "Okay, you go to the hardware market first, and I'll take the time to come over." ”

"Thank you, Mr. Wang."

Jiang Hao was about to go out, but was bumped into by Ma Dong, and he had to follow. The reason is that there is no class today and Saturday, and he wants to go out to feel the ripples of the spring breeze.

"You're not playing Dota in your dorm?" Jiang Hao was puzzled.

"Don't play, go out for a walk, and go to those dates by the way."

"Are you progressing so fast with Zhang Lingling?"

"Take precautions, although I haven't confessed yet, she is willing to chat with me, which shows that there is a spectrum in this matter."

Looking at Ma Dong, who was full of confidence, Jiang Hao was speechless.

He belongs to the kind of licking dog that Zhang Lingling has a "um" word, and he can make up five pronunciations in his brain.

The two took the bus for more than half an hour to enter the city, and then transferred to the bus again before rushing to the hardware wholesale market in Yangcheng.

For hard-pressed students, taking a taxi is too luxurious.

"Jiang Hao, Ma Dong, here!" Wang Chaoyang stood across the street and beckoned to them.

The two of them crossed the road and walked towards Wang Chaoyang.

"Hurry up, I can only roughly teach you how to choose materials, and I have something to do later." Wang Chaoyang said as he looked at his watch.

Wang Chao pulled the two into a shop selling cast iron profiles.

"This shop is the largest iron shop in the wholesale market, and most of the materials for our school are bought from here." Wang Chaoyang introduced.

The boss also greeted him very familiarly.

Wang Chaoyang said: "In machining, technology is very important, but there is another thing that is also very important, that is, the familiarity with the processed materials.

There is a trick to choosing materials: look at it, touch it twice, and listen to it three times.

To look is to observe the surface and cross-section of the material to see whether the gloss is full and whether the material is compact. To touch is to pick it up and weigh it, and compare the weight difference between two identical materials. To listen is to knock on it, to see if the sound of the material is low and crisp. ”

After saying that, he picked up the two steel rings and hit them lightly, making a buzzing sound.

"A truly experienced master can tell by his voice whether there is trachoma or cavities in the material.

Of course, the teacher doesn't have that strength yet. Wang Chaoyang said with a smile.

"Going back to the materials you are looking for, generally speaking, forged steel and cast steel are used more to make gears or bearings, but both of them need heat treatment after processing. It is normalized or quenched.

Our school does not have that process condition, and these two materials are not considered.

There is also a kind of ductile iron, which can meet the requirements of low speed and medium load use with its mechanical properties and impact resistance. We are the only one who has ductile iron here, you..."

He was talking vigorously when the phone rang.

"Hello?" Wang Chaoyang covered the microphone and turned around.

“... Okay, I got it. ”

He hung up the phone and said to Jiang Hao and the two: "The teacher still has something to do, you pick it slowly." Keep the invoices and receipts and go back to me to report the bills..."

With that, he hurried out of the shop.

Jiang Hao and Ma Dong were dumbfounded: This is leaving?

"Brother Hao, I think there must be something wrong with Lao Wang, let's go ahead and take a look?"

Jiang Hao shook his head: "It's not good." ”

The two looked at each other and smiled, walked to the back of the store with their waists bent, and observed through the crack in the door.

Wang Chaoyang trotted all the way across the street, and there was a shy Zhou Liping standing on the other end of the street.

"Holy, Teacher Zhou!" Ma Dong called out, "I said a long time ago that the two of them had an adulterous affair!" ”

Jiang Hao: "One is unmarried, the other is unmarried, how can it be called adultery." ”

Ma Dong: "Teacher Zhou is so fierce on weekdays, but today he is like a bird." Gee. ”

Jiang Hao: "Lao Wang really has a set. ”

Ma Dong: "I have to take a sneak peek." ”

Watching the two walk away arm in arm, the two straightened up.

I've seen enough of the excitement, but I haven't done anything yet.

"Boss, do you have ductile iron with a diameter of about 15 centimeters and a length of about 10 centimeters?" Jiang Hao asked.

The boss smiled: "Most of us here are profiles, and the specifications you mentioned are really not necessarily there." ”

Iron profiles are generally long cylindrical or square columns, which are bought as a whole and are not cut individually.

He stroked his Mediterranean hairstyle and said, "That pile of scrap may have the specifications you want." ”

Following the direction of the boss's finger, Jiang Hao saw a pile of various waste materials piled up next to the back door.

It is said to be waste material, but it is actually a broken joint or a finished part with a gap and defect that is cut from some damaged profiles.

Jiang Hao and Ma Dong wore gloves and rummaged through it for a long time, and finally found a few sections of ductile iron materials.

They wanted to get all this back, but the boss said that they would be weighed and sold at the price of ordinary cast iron, which would cost hundreds.

Besides, it's too heavy for them to get back.

"Why don't I try to pick the best ones?" Jiang Hao said.

The boss smiled beside him: "Young man, do you still pick materials?" ”

Jiang Hao ignored him and selected materials according to Wang Chaoyang's teaching.

At first glance, there is a layer of light iron ash on these waste materials, and you can't tell whether it is good or bad.

Two touches, one touch a handful of ash, useless.

After listening to it three times, he used a rope to lift the two materials and bumped into each other, trying to feel what was inside the sound with his heart.

Suddenly, the system panel popped up.

[Host: Jiang Hao]

[Skill Card 3: Listening to the Defense]

[XP: 6 points]

[Rating: Primary]

[Evaluation: At this level, it is half a deaf person]

Listening to the argument?

What the hell is this?