> 2.3-millimetre

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

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.

" 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...