pitted ball screw

I just received a used ball screw bought off you-know-where. The screw (no name on it) is a 26" long 3/4" OD, 2 start, .5" travel per revolution. It seems to have no backlash, and turns very smoothly, except in two or three areas, a few inches apart from each other, where I can see minor pitted spots on the troughs of two or three of the threads, -- actually seems to be every other thread in these spots. It still turns easily through these areas, but i can feel a little resistance in these spots. This router is to be used for woodworking, though planned to do inlay, so reasonable precision will be required. Are these pitted areas apt to cause a problem? Can they be smoothed out somehow (with a round file, perhaps?) or would that make things worse? Thanks!

What ever you do, don't use a file! Try to smooth down any high spots or damage with a fine honing stone and oil. Atlernately wrap some very fine emory paper around the round file, use oil as a lubricant, and slowly and carefully try to blend it out. Clean the surface and test how it runs often as you smooth it.