[KTL]

Which oil line are you planning to repair with the nut? Reason I ask is because if its a line with a rubber section, you can cut the collars off the rubber section and have new hose installed at a hose shop. While you've got the line apart, slip off the nut and clean it like JW said. Or heat it up real hot and pick the aluminum out with a pick tool & some oven mitts.

If you already cut the old nut off, I believe I have some of those original size nuts in my collection for just this reason. But in order to use the used nuts I have, again you have to take apart the hose section.