So...
Maybe some of the heads who have experience machining metals can address this.
Regarding the aftermarket kingpin re-threader that can be purchased as part of a set, along w/ the axle re-threading die: after a kingpin has been ground down a bit & the top is shaved into a wedge, can you even employ/utilize the re-threader in that situation? If the die can only "catch" the edge of the thread that is highest/closest to the axle, will it be able to chase the threads?
I get that a mushroomed off axle-end can be touched with a file & the chased, but the kingpins get scraped down at a bit of an angle, comparatively.
Anybody have any knowledge 'bout that? Maybe wanna share?