# Metal on Metal Friction Fit Cap?



## Chewy3939 (Jun 3, 2015)

I'm currently in the process of designing a pen. I am having difficulty finding a way to post the pen's cap. I am designing it to be similar to a Jr Gent II. However, I do not want any exterior threads visible. I will be using threads to attach the cap to the grip. Additionally, the entire cap will be metal; I will only be making one wood barrel. Is it possible to have a friction fit cap when both the cap and the end cap are metal? I don't want it to mar either the end cap nor the wood barrel with a CA finish. If a friction fit won't work, what do you recommend?

Thank you! I sincerely appreciate any help you could offer.


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## BRobbins629 (Jun 3, 2015)

A friction fit will almost always leave a mark but here are some ideas. 

1.  put a soft plastic insert such as delrin in the cap to help. 

2 polish interior of cap to real smooth

3 use  a softer metal on the cap than on the lower barrel.


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## thewishman (Jun 3, 2015)

Will the female threads ion the cap be metal or an insert of softer material? Either way, design the bottom of the pen to be small enough that the cap will slide on. You don't want metal threads to scratch either the metal end or the wood, so a taper inside the cap should match the posting end of the body.


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## Curly (Jun 3, 2015)

Fisher Space pens have metal cap and barrel. The cap friction fits over an "O" ring on the barrel. Would something like that work for you?


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## Chewy3939 (Jun 3, 2015)

Im sure it could get the job done but its not the style I'm going for. It gets me thinking about putting gaskets inside the cap though...


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## KBs Pensnmore (Jun 4, 2015)

Chewy3939 said:


> Im sure it could get the job done but its not the style I'm going for. It gets me thinking about putting gaskets inside the cap though...



What about putting an O ring inside the cap. Machine a groove inside the cap for the O ring to sit in, small diameter (thickness) rings should be available from local auto parts stores.
Kryn


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