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I have a funky old pen where the threads on the barrel have worn away.

enter image description here

The barrel body and cap are mostly brass. The "business end" of the barrel, in the middle of the picture, is plastic except for the tip, and its plastic threads screw into brass threads in the barrel. The refill is pushed against the barrel tip by a strong spring behind the other end, so it always stresses the threads. The tip snaps tightly into the cap, so every time the cap is removed, it pulls against the threads.

Over the years, the plastic threads have sheared off. Even though you can still see some thread ridges in the picture, it's now at the point where there isn't enough thread height to hold the end in the barrel, it just slides in and out of the barrel.

I assume the pen was made with some generic internal pen hardware (it isn't a brand name pen). I'm guessing that all such pen hardware does not conform to universal standards, so there would not be a simple way to just buy another barrel end and expect it to mechanically match.

I've looked at ways to build up the plastic to create some type of sleeve that could mold itself to the brass threads, or use the barrel to cut the threads. Another approach might be to mold an insert on the brass threads that could be bonded to the plastic stem (would probably require reducing the diameter of the plastic threaded area). As a last resort, I could always put in a new refill and glue the barrel shut to get as much final use out of it as the refill lasts.

Before experimenting with those solutions, I'm wondering whether there is already a standard fix for this. For example, are there just a few makers of pen kits, and replacement barrel ends are, in fact, available (based on measurements since the kit can't be identified)? Or, have people already figured out a solution for fixing these?

fixer1234
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  • It's unlikely that one can use the threads inside the pen to cut new threads on an enlarged plastic mid-section. There must be a means of clearing the debris created by cutting threads and a continuous thread will not work as a cutting agent. – fred_dot_u Jul 15 '22 at 08:48
  • To me it seems like this question is in a grey area between Arts & Crafts and Lifehacks – Elmy Jul 15 '22 at 09:28

1 Answers1

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This sounds like a job for a denture-reliner kit. It won't be a permanent fix and will need to be repeated, but it should give you a good, solid connection between the two parts that will hold well. Depending on how often you unscrew the parts, I'd imagine you'd only have to repeat this every six months to a year.

  1. Choose a denture-reliner kit that gives you a powder and a liquid to combine together into a gloopy substance that can be applied to a denture.
  2. Follow the instructions for combining the ingredients into the gloop.
  3. Apply a coating of the gloop around the insert of the pen that goes into the barrel.
  4. Screw the pen together.
  5. Wipe off any excess gloop with a damp cloth.
  6. Wait the amount of time it says to wait in the denture-reliner kit's instructions (usually a few minutes).
  7. Unscrew the pen and set the pen part somewhere to dry and set (I'd give it at least half an hour and preferably a few hours).
  8. If there's any excess gloop that you didn't manage to wipe off properly, it can be trimmed off with scissors or a craft knife.
  9. If you don't like the end result or would like to do the job over with some fresh gloop, hot water and a bit of elbow grease will remove the stuff from the pen.
Little Girl
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