Profile's 22mm Column spindles are legendary The "Inside Profile Racing" series dives into them:

"This episode will cover the initial 7 steps of the first process of our 22mm Column Spindles. Timing on the first process for steel: 5:20. Timing on the first process for titanium: 16:30. After this process, the spindles will be taken to another machine where they are threaded. If steel, they will then go on to get heat treated (3rd process), black oxide will be applied (4th process), and finally, laser etched (5th and final). If titanium, to a final (3rd) process of laser etching."