I came up with this simple trick to give PVC pipe a realistic wood texture when I built a few plastic didgeridoos a couple of years ago. It would also work for theater, home decor or backyard tiki-bars! Send an invite if you build that last one.
Use a triangular file to create a die out of any nut. A die is used to restore the threads on a bolt. You should carefully screw it onto and back off of the damaged threads, using a few drops of oil to lubricate. Remove the metal shavings.