a pipe cutter leaves a flange on both sides. it works by displacing the metal, similar to cold forming
Yea Hard steel wheel with a sharp edge, rolls around and pushes softer metal out of the way,
so it gets displaced somewhere .. some goes up, like spokes , rolling in threads,
to be larger than the diameter of the stock, , and some of it pushed Inwards.,
making the Star or expansion nut harder to install.
NB you can just add a couple CM of spacers and fit them above the stem.
and not cut any thing off.. since it wont grow back,
if you change your mind a few years later.