Cap threads. Delrin or ebonite?

[AurelianC]

Started 2 new fountain pens today with the idea to make the section in wood. After cutting some tubing for the body and cap and choosing the wood it hit me. If I make the cap threads from aluminium it will scratch the wooden section.
What I have in the shop is ebonite and delrin, so which one is more durable and will not scratch my wooden section.
If you know other materials that will do the job better please share.

Thank you.

 

[BRobbins629]

Both should work, but it will be easier to glue in the ebonite. Delrin will require a press fit that may not last.

 

[AurelianC]

Thank you Bruce.
I was planning to make the threaded sleeve quite long so it will have more surface cu adhere.
Thank you for the reminder that CA and delrin do not bind.

 

[frank123]

Delrin would be more durable but you would probably be wise to cut a few grooves or even threads -radial and axial- to provide a mechanical as well as adhesive lock.

If you have a plastic supply house nearby, some ABS rod would work wonderfully.

I've used both ABS and Delrin on stuff like this (not pens, just various other things I have made) but have never used Ebonite that way so I can't say anything about it.