Threading

[keithbyrd]

When making a kitless pen I am concerned about the strength of the barrel threads. When drilling and threading the barrel for the cap and the section, that part gets pretty thin and fragile. I made one a few years ago (my first and only until recently.) and opted to make the threads out of aluminum. What is the general feeling about using aluminum for that part? I used a section from a jr series for this one.

 

[jalbert]

I don't like the look, so I won't do it. If that's what gives you peace of mind though, there's nothing wrong with it.

 

[Hippie3180]

Are you using single, triple start? What material? I've done single and now do triple and despite the delicate nature they hold up fine. I use Alumilite though so not sure about other materials.

 

[rixstix]

I haven't seen the thread sizes that are causing your issue?

I use m9.5 for section threads and m12 for cap/body threads without a hiccup. Single start. Acrylic, Alumilite, Kirinite & PR.

Like John, I don't care for the aluminum look but if that is what you need, it's up to you.

 

[Hippie3180]

I also wonder if your getting your walk to thin, if your having breaking of your tenon after threading.

 

[keithbyrd]

Are you using single, triple start? What material? I've done single and now do triple and despite the delicate nature they hold up fine. I use Alumilite though so not sure about other materials.

triple start - I have not had any breakage - just concerned about it being so thin/fragile - don't want a customer to send it back with broken threads!

 

[keithbyrd]

I haven't seen the thread sizes that are causing your issue?

I use m9.5 for section threads and m12 for cap/body threads without a hiccup. Single start. Acrylic, Alumilite, Kirinite & PR.

Like John, I don't care for the aluminum look but if that is what you need, it's up to you.

Rick - i used M9x 0.75 for the section threads and M11 -.8 for the Cap body threads - I don't have an M12. I have an M13 tap but no die

 

[rixstix]

Rick - i used M9x 0.75 for the section threads and M11 -.8 for the Cap body threads - I don't have an M12. I have an M13 tap but no die

Yep, that's not much meat left with that m9/m11 combo. m9 didn't leave much room to my liking for ink cartridges.

 

[jalbert]

Rick - i used M9x 0.75 for the section threads and M11 -.8 for the Cap body threads - I don't have an M12. I have an M13 tap but no die

I would encourage you to learn how to use that nice new metalworking lathe for single point threading
You'll never need to worry about having the right tap or die again

 

[Aurelius]

One thing to keep in mind if you do stick with the metal section and a resin body is that, over time, the section thread will act like a tap and cut a bit further into the resin each time you screw it in. It might not be a big deal but it cold also lead to your section fitting getting looser over time or, worst case, splitting the body material if you go too far and overtighten the section.

 

[keithbyrd]

Yep, that's not much meat left with that m9/m11 combo. m9 didn't leave much room to my liking for ink cartridges.

I did find a M13 die - how will that do with m9
How do I determine what tenon size and drill bit to use?

 

[jalbert]

What kind of section are you making? Rollerball? Fountain pen with #5 nib? Fountain pen with #6 nib? 9mm section tenon should be fine for a rollerball since you only have about a quarter inch hole running through it (depending on what refill you use). For fountain pens, it would probably be ok with a #5 nib. For a #6 nib I would bump it up to 10mm diameter. With a 13mm cap thread there really isn't any reason you couldn't just use a 10mm section regardless, to be safe, unless you don't have a 10mm die.