I started with a ship full of max-level veterans, and I'm just a complete noob.

When the first cut actually made its way into the copper surface, Lao Sun had already slowed his breathing to its shallowest. The lathe spindle was rotating at a constant speed, and each turn of the feed handwheel was 0.02 millimeters. His fingers remembered the resistance transmitted back with each turn, so he didn't need to look down at the dial.

The blade tip brushed against the copper surface, and a uniform circle of fine threads rolled out from under the blade and fell into the chip collection tray. Each thread was the same width and the same curvature, gleaming with a dark red light under the lamp.

After finishing the first eccentric hole, Lao Sun loosened the chuck clamp and tightened the handle, pulled out the locking pin of the indexing plate, and turned the worm gear handle nine and three turns, precisely corresponding to the forty-five-degree indexing angle.

The locking pin fell back into the positioning hole with a very faint metallic click.

When the second hole was cut, the trace left by the cutting tool overlapped with the edge of the first hole, and a crescent-shaped notch slowly formed on the surface of the copper billet.

Da Liu stood two meters away, clutching a handful of clean cotton yarn in his hand. He dared not get too close or make a sound, and just stared at Lao Sun's back.

For each increment—the third hole, the fourth hole, the fifth hole—Old Sun would touch the edge of the pin hole with his finger before pulling out the locking pin to make sure no copper shavings had fallen in before turning the worm gear.

When he finished turning the sixth hole, Lao Sun stopped, took out a piece of degreased gauze from the toolbox, and wiped the copper shavings off the cutting edge of the tool.

The blade reflected the light; there were no chips or signs of wear.

Oxygen-free copper has exceptionally good cutting performance. Unlike ordinary copper, it doesn't stick to the cutting tool. After the cutting tip passes through it, the surface is so smooth that it almost requires no further repair.

Only after Lao Sun used an air blower to clean the last bit of debris from the seventh and eighth holes did Da Liu dare to approach.

Eight crescent-shaped notches are evenly distributed on the end face of the copper billet, resembling a symmetrical flower.

However, this is still just a rough blank. At the corner connecting the crescent-shaped cavity and the inner hole of the anode, the arc of the lathe tool cannot cut out the right angle transition required by the theoretical drawing. The remaining allowance of 0.1 to 0.15 millimeters must be scraped by hand.

Old Sun pulled out a set of scrapers from the bottom of the toolbox. He had sharpened them himself, with a blade tip width of only 1.5 millimeters and a cutting edge angle of 30 degrees, specifically designed to deal with the dead corners in such narrow grooves.

He removed the copper billet from the chuck, fixed it in the bench vise, bent down to bring it to the same height as the billet, held the workpiece steady with his left hand, and held the scraper with his right hand, pushing away the excess material at the corner bit by bit.

After every three cuts, he would stop and use a 10x magnifying glass to check the texture of the cut surface to make sure there were no rough edges before continuing.

This process lasted for nearly two hours.

Liu brought over a bowl of water, but Sun didn't take it. He just waved his hand, telling him to put it on the table.

After the last ridge of the eighth cavity was finished, Old Sun slowly straightened up, and his lumbar spine made a muffled sound.

"micrometer".

Jiang Ming handed over the micrometer, which Lao Sun took and measured the radial depth of each of the eight cavities.

8:18, 8:17, 8:18, 8:19, 8:18, 8:17, 8:18, 8:18.

The maximum deviation is 0.02 mm, which is exactly within the upper limit of the tolerance zone allowed by the drawing.

The seam width was measured using a plug gauge. Old Sun combined 0.05 grade plug gauge pieces into a thickness of 2.06 millimeters and inserted them one by one into the eight seams. Each one slid in perfectly without any noticeable wobble.

"Passed."

Old Sun put the gauge back into the box, turned to look at Jiang Ming, and his voice was a little more relaxed than before.

"Mr. Jiang, the dimensions are all within the acceptable range."

Jiang Ming filled in the last number on the inspection record form and signed his name.

"Next step, acid pickling."

Xiao Zhao is already waiting next door.

The No. 2 copper deionized water column was built three months ago during the research and development of the type B pipe. It is now operating very stably, and the conductivity of the output water is consistently below 0.5 microsiemens per centimeter.

The automatic rinsing line is a frame that Da Liu welded last month. It uses stainless steel pipes for the frame, a high-level water tank for water supply, a bottom receiving tank for waste liquid recovery, and a polyethylene bracket in the middle to support the workpieces to be washed.

Xiao Zhao opened a bottle of anhydrous acetone, poured half a bowl into an enamel basin, and then used a cotton ball to carefully wipe the inner wall of each cavity of the anode blank.

"Go through the degreasing process twice. The first time, apply a rough wipe, and the second time, use fresh cotton pads."

He muttered the procedure to himself, his hands moving quickly but not carelessly. A thin film of acetone was left where the cotton had been applied, which quickly evaporated.

After degreasing, Xiao Zhao put the anode blank into a glass beaker containing a 5% dilute nitric acid solution that Da Liu had prepared in advance.

"The pickling time is 30 seconds, and it should not exceed 40 seconds. If it exceeds this time, the surface will be over-corroded."

Xiao Zhao glanced at the stopwatch hanging on the wall.

"Timer begins."

The moment dilute nitric acid comes into contact with the copper surface, a layer of extremely fine bubbles appears on the surface; these are nitrogen oxides released when the oxide layer is dissolved.

At 32 seconds, Xiao Zhao took the blank out of the acid solution and immediately immersed it in a basin of clean water next to him for the first neutralization.

Then comes the main event.

Da Liu opened the valve of the rinsing line, and the deionized water in the high-level water tank was sprayed evenly from the nozzle. Xiao Zhao hung the anode blank on the polyethylene bracket, allowing the water to flow into each cavity from the top and then out from the bottom.

"Two hours of continuous rinsing, with water running non-stop in between."

Jiang Ming stood beside him and checked the parameters again.

"Is the water tank full?"

Da Liu looked up at the water level gauge.

"That's enough. We made four hundred liters yesterday."

Xiao Zhao opened the duty log and wrote a few lines in the record column for the day: 400 liters of water produced, calcium hardness not detected, conductivity 0.38 microns.

The two-hour rinsing process was not particularly dramatic; there was only the sound of flowing water and the occasional metallic clanging sound when adjusting the showerhead angle.

But it is precisely this tedious, precisely timed industrial process that transforms a hand-cut copper piece into a precision component that can be placed in a vacuum system.

At 4:30 p.m., the anode blanks were removed from the washing line.

Xiao Zhao used a conductivity meter to measure the residual liquid of the last drop of rinsing water. The reading was 0.42 microSiemens, which was almost the same as pure water, indicating that there were no detectable chemical residues on the surface of the workpiece.

The anode blanks are placed in a preheated drying oven, with the temperature set at 60 degrees Celsius and the time set at 30 minutes, to drive away the water molecules adsorbed on the surface.

The observation window of the drying chamber is small, but even through the glass, you can still see the color of the copper piece under the warm yellow light.

It was a pure red, like molten copper wrapped in silk, its surface so evenly glossy that not a single scratch or blemish could be found.

Old Sun peered through the observation window for a few moments, then stepped back, letting out a satisfied hum.

"Engineer Jiang, this is the first anode blank in our country that can be fitted with a magnetron."

Jiang Ming didn't respond to that. He was holding a micrometer, checking the dimensions against the drawings for the final verification, re-measuring the depth and width of each cavity to ensure that no slight deformation occurred during the drying process.

When the data was being filled into the seventh cavity, the side door of the workshop was knocked on three times from the outside.

Da Liu went to open the door, where a communications officer in a gray cotton-padded coat stood, holding a letter in his hand. The envelope was stamped with the red seal of the Confidentiality and Security Department.

"Comrade Jiang Ming, Director Wang asked me to deliver this; he said it's urgent."

Jiang Ming put down the micrometer, took the envelope, and glanced at the seal and date on the back.

Today's date, stamped at 3 PM.

He tore open the envelope, and inside was only a note in Director Wang's handwriting, with two lines of text written on it.

Old Sun glanced over his shoulder but couldn't see anything clearly.

Jiang Ming folded the note and stuffed it into his work uniform pocket. His face showed no obvious change in expression, except that his fingers paused for a moment outside the pocket.

"Old Sun, please fill in the remaining data for the cavity review. After it comes out of the drying chamber, wrap it in wax paper and put it in the safe."

Old Sun was still holding the record sheet when he heard this, and he looked up at him.

"Are you leaving?"

"Director Wang has something to attend to, I'll go over there."

Old Sun watched him walk out the side door. The rain had stopped, and the sky was a grayish-blue color. The water on the tin roof was still flowing into the eaves gutter.