When you get the new ones, compare them to the existing ones. If they feel/look the same, then the existing are aluminum, as well. Keep the new set for the future since the existing ones still have plenty of life left.
I like to replace them when they are about half way eaten up. You can sretch that a bit, but unless it's near the end of the season, it's not worth it.
I like to replace them when they are about half way eaten up. You can sretch that a bit, but unless it's near the end of the season, it's not worth it.