I have struggled, many times, to fit a steering stem onto a handlebar. As often as not, the stem is so tight that it damages the bar during assemble, scratching the heck out of the handlebar.

That happened, today, when I installed this TTT stem on this TTT Touriste handlebar. With a small flat smooth file, I cleaned up the scratches on the non logo side of the bar, hit it with some high gloss jeweler's rough and it turned out looking OK, but I would rather not have to do the file and clean up work again, if I don't have to. Does anyone here have any suggestions for how to facilitate this ornery task?