What's pretty much the best-performing major industrial product in China this year?

Industrial boilers for coal power plants:

https://data.stats.gov.cn/english/tablequery.htm?code=AA0701

Only industrial tractors, primary plastics and "power generating equipment" (much of it the non-boiler bits of the coal-fired power station) have shown a faster cumulative year-on-year growth in output.

Output in November was insane. The highest level in the data I can see, up about 2/3 month-on-month or year-on-year.

The volume of coal boilers manufactured in China *this year alone* would be sufficient to burn all the coal that Europe or the U.S. used in 2020.

And that's just the *incremental supply of new boilers*, on top of all the ones already in operation that consume half the world's coal.

(I'm basing this on the assumption of 6 tonnes steam/tonne coal and an admittedly unrealistic 100% load factor, which gives you enough boilers to burn 448m tons/year of coal)

Small clarification: Not all industrial boilers will be coal -- they can also burn oil or gas. But in China, all but a handful will be coal, and this data matches estimates of the huge coal buildout gathered by @laurimyllyvirta and others.

This may also help explain why steel production is booming and iron ore prices at $175/ton. Boilers are made from 3.5cm-thick steel plate to withstand the steam pressure.