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by OneDonOne 27 days ago
It is not the pen, it is the pen tip. Ballpoint pen tips are microscopic tungsten carbide ball held inside ultra-thin steel sockets. So you need cutting tolerances precise to 0.001 millimeters. If the socket is a fraction of a micron too loose, the ink leaks. Too tight, and the pen won't write.

Source from al-Arabiya: https://english.alarabiya.net/variety/2017/01/14/At-last-Chi...

The point (no pun intended) is that China was beginning to crack the processes for making the precision machine tools that make machine tools.

3 comments

The ballpoint pen was invented in 1938. It doesn't rely on any arcane manufacturing technology.
I am 47 and ballpoint pens have visibly improved since the 1990s, at least the cheap ones (never had an expensive one). The risk of accidental staining is by now basically zero, it used to be high enough that you avoided putting a pen into your shirt pocket even for an hour.
Hence the fading away of the "nerd with pocket protector" stereotype...
They do. The micro-precision subculture required to (in order):

1. Powder prep your tungsten carbide

2. Form said powder

3. Thermally prepare the resulting slurry using a vacuum forming furnace

4. Finish it with diamond lap grinders, lapping machines and polishing machines

5. Clean it ultrasonically, with solvent, rinse, then dry them.

6. Have the metrology required to test thousands of micron-scale balls a day (a world-beating skill in itself)

7. Build a QA lab that can assure the quality of said balls statistically (you can test them all).

8. And then integrate them via socket assembly

are not just hereditary, but proprietary. And assuming a competitor does manage to achieve the basic ISO 3290 and ASTM F2094 standards, you still need tacit knowledge. Stuff like sintering temperature curves, proper powder grain distribution, polishing chemistry, proper statistical rejection thresholds and a whole lot more.

And that is just the ball. Not the socket, or the ink channels. Making a perfectly spherical 0.5 mm ± 0.0001 mm tungsten carbide ball requires the same techniques used in building micromotors, medical devices, and semiconductor subcomponent manufacturing. Techniques such as high-volume sorting, advanced powder metallurgy, controlled sintering, and precision machines that operate 24-hour shifts without drifting. All operated by modern process engineers who are the spiritual (or actual?) descendants of Swiss watchmakers or the glassmakers of Murano.

They are not microscopic! I can easily see the balls in the tips of ballpoint pens.
The ball is not microscopic, but the tolerances required to make the ball spherical and fit into the socket are.
Exactly, so this sentence is incorrect:

> Ballpoint pen tips are microscopic tungsten carbide ball held inside ultra-thin steel sockets

Yes indeed, you are correct. My mistake.
The BBC article even mentions that they are milliscopic, not microscopic.

> 2.3-millimetre

China's ballpoint pen quality as a reflection of manufacturing quality:

" China's inability to produce a complete, high-quality ballpoint pen came to widespread attention in 2015, when Prime Minister Li Keqiang singled out the products at a seminar in Beijing, noting that his writing was "rough" when he used Chinese-made ballpoint pens. For Li, China's failure to manufacture a complete ballpoint pen was indicative of the Chinese economy's weaknesses. "That's the real situation facing us," Li said at the time. "We cannot make ballpoint pens with a smooth writing function." "

https://www.smh.com.au/world/finally-china-manufactures-a-ba...