What does 1K, 3K, 6K, 12K, 24K mean in carbon fiber industry?

Carbon fiber filament is very thin, thinner than people’s hair. So it is hard to make the carbon fiber product by per filament. The carbon fiber filament manufacturer produce the tow by bundle.
The “K” means “Thousand”. 1K means 1000 filaments in one bundle, 3K means 3000 filaments in one bundle. So as other sizes. 3K plain weave is a typical look of carbon fiber.
This number is almost meaningless for the carbon fiber tube / pole users. Because we only use pre-preg carbon fiber cloth which is made by the pre-preg process factory, who combines the carbon fiber with resin.

The most popular one in carbon fiber tube / pole business is 3K plain weave which is cloth is made by 3K carbon fiber.