Originally Posted by Wil Davis
Swarf (or turnings) is the debris or waste resulting from metalworking operations. It consists of shavings and chippings of metal. If the holes drilled in the rims have not been "de-burred" sufficiently, swarf can be left on the edge of the holes.
- Wil
I have some Velocity rims that have some small rough spots/gouges around the seam where the rim was joined. I originally was using Veloplugs with these rims, which cover the spoke holes very nicely. But the rough spots actually wore a hole in one of my tubes, so I replaced the Veloplugs with 17mm Velox. So far it has been working.
So the moral is to make sure all rough spots are covered, not just the spoke holes, or else de-burr them manually.