Fountain pen retaining piece

[Stugots]

Does anyone have a source for the plastic part that holds a PSI "Traditional" style Fountain pen closed? It screws to the inside threaded part of the clip and can be adjusted using a screwdriver but are very fragile. I am having trouble getting them on without cracking them to where they are no good.

 

[Dustygoose]

I broke one before and bought a replacement from Craft Supplies. Use a small flat tip screwdriver. Or screw it on a few threads then put it in the cap from the top.
Be sure to cut notch for the clip first. Once it's pressed in, Use the small flat tip to adjust the cap for the perfect snap

 

[frank123]

If we're talking about the same thing (which we may not be), a snap cap is what I'm thinking.

Tapping the snap cap first to make sure it threads on straight works best for me (you can use a real tap or just a screw with the end side ground a bit flat to make a cutting edge)

I've found a large Phillips screw driver to work well at adjusting it after screwing it fully on the finial and putting the whole the assembly in place (just slowly unscrew while testing the fit till the cap snaps on the way you want it to). Standard flat bits seem to be more likely to break it.

 

[monophoto]

It's called a 'snap cap'. It's intended to be installed using a special tool sold by the vendor, but you can also use a #2 Phillips screwdriver. Better yet, if you are a Subaru Forrester driver and bought a roof rack with your car, the Robertson screwdriver that comes with the roof rack is the perfect tool.

I really dislike snap cap designs on fountain pen kits - they tend to loosen or tighten on their own, they don't seal the pen well enough to prevent ink evaporation, and they are a PITA to install. I've found that using a tap to thread the plastic nib before installing is easier than trying to use the stud below the pen finial as a tap, but the downside is that if you thread the nib too well, the tendency to loosen/tighten increases. Applying a drop of CA before assembly sometimes helps. And once you have installed the snap cap, disassembly becomes a real challenge - attempts to disassemble the pen usually end up destroying the snap cap.

A while back I placed an order for some kits at CSUSA, and requested some spare snap caps to replace some that I had broken. They provided them at no charge.