I know this has been stated here before, but, sorry, I can't seem to search up all the info I need, and the one figure I found doesn't appear right. So might someone in the know confirm or correct the following thread sizes for the Parker 51?

Hood: 11/32 inch, single lead 48 tpi
Vac blind cap: 5/16 inch, single lead 36 tpi
Aero barrel: 3/8 inch, three lead 48 tpi (16 tpi per lead)

Also, who is the best source for taps and dies for the correct sizes? TIA!

You will most likely need to have the taps/dies custom made. Parker tended not to use standard thread sizes and none of the ones you list are standard.

You might try Widell, if they don't have it, they can make it.

Todd

Yes, I'm aware of that, but for the short runs involved, "close enough is good enough". A well known pen restorer indicated that, for instance, a 32 tpi thread could be used for the 36 tpi filler stub, given the very short run involved. So I'd like to know the closest inch/tpi parameters for the indicated sections. Thanks!

I can confirm the following threads specified for external cutting. The values given are major diameter (D) and tpi:

Hood 0.351 - 48 (single lead) (This is the same as the barrel end of a vac filler)
Blind Cap 0.304 - 36 (single lead)
Aero Barrel 0.368 - 48 (triple lead)

By confirm I should state this is what I cut to make polishing mandrels for the above parts. I do not know if these are the exact measurements Parker used but they worked for me.

Todd

Sort of related- can use a Vacumatic wrench to remove the vac filler from a Vacumatic 51?

Yep!

Cheers,
Tom

Yes - the debutant vac filler was used in the debutante, Jr, Major as well as the 51 vacumatics. Which BTW, is why you should use the deb diaphragms in all of the above. I stock far more of these than the other two sizes.

That's what I was looking for, thanks, Todd.

Todd,

Are you making these mandrels yourself and would you consider making a some for sale? I'd be very interested in these and perhaps some for vacs & duofolds.

John

Thank you. I have diagrams in deb. size, last time I checked 51 Vac's take those.