Originally Posted by
special_20
...I was not able to identify any "helical ridges" on the steer tube. What are these helical ridges (hone marks, butting ridges)? Are they identifiable by touch or should they be pretty obvious visually?...
They can be hard to discern visually if the inside of the steerer tube is dirty or corroded, as they are only 3.5mm wide by 0.35mm thick. Here's a picture of a Columbus steerer tube, with the helical ridges in pristine condition.