Sheaffer O-rings

[KendallJ]

OK, I know that several pen restoration guys resell the o-rings for Sheaffer snorks (and in fact have purchased from them). However, does anyone know the specs on the O-rings? I have to imagine that these are available from O-ring distributors at a much lower cost. I'm thinking here of both the point and barrel o-rings.

[Guest Denis Richard]

I don't have the answer, but if you have some of these O-rings, I would suggest to take them to your local hardware store. It should take only few minutes to find out.

[ElaineB]

I checked every o-ring in every hardware store I could find a couple of months back. The Sheaffer o-rings are far smaller than anything I found available.

 

I remember that Richard Binder gave the specs for them around that same time on Pentrace, but the info has sadly scrolled off into oblivion. Perhaps it's been mentioned in the Zoss List archive, though?

 

I found o-ring distributors online, but you had to buy literally thousands of them as a minimum order. I finally bit the bullet and ordered them from Dave Nishimura. It's cheaper to do it through his eBay store than his website. His are also a more durable polymer than black latex, so they shouldn't need replacing for a long time.

 

ElaineB

[Dillo]

Hi,

 

David Nishimura lives in the same state that I live in. http://www.vintagepens.com

 

Dillon

[KendallJ]

Posted on PT and Richard gave these specs. I'll post it here so it won't scroll off the page!

 

Posted by Richard on July 26, 2005, 7:54 pm, in reply to "Specs on the Sheaffer TD/Snork Orings"

 

Snorkel and Touchdown TM (including Imperials) take 7 mm I.D. x 1 mm cross-section.

1949 Touchdown and PFM take 8 mm I.D. x 1 mm cross-section

[KendallJ]

$0.08 a pop at this location. Minimum of 63. Buna-N (nitrile) not EPDM

 

http://www.air-oil.com/oringsonlinefset.htm

 

I'll keep looking.

[Gerry]

If you're looking for a partner to split an order with Kendall, I'd be happy to oblige. That is as long as you don't think you'll need 63 of them yourself.

 

Gerry

[ElaineB]

Kendall, that is SO cool!! "O-rings Online" -- who'da thunk such a place existed?! (I was looking at plastics distributors and manufacturers which had HUGE minimums.)

 

Thanks for the info. I've filed it for future ref!!

 

ElaineB

[KendallJ]

All I can say is "Google rocks!"

 

I'm considering putting in an order. I'm finding that when I get TD's and Snorks in that are "restored" it does not always include the O-ring replacement, and frankly, they almost always could use it.

 

I would like to find EPDM in metric sizes, but haven't yet. I'm pretty sure the Buna is std material, and these rings will only see silicone grease.

 

I wish the snork point O-rings were easily available, but Richard says he doesn't know the size and has to order them custom. Anyone out there with a micrometer and a snork? Please mic the snorkel tube OD, and the point seal channel OD!

Edited July 27, 2005 by KendallJ

[whv]

shamelessly borrowed from the baxter rubber web site:

 

"Nitrile (Buna-N, chemical definition: Butadiene Acrylonitrile) is a general purpose oil resistant polymer which has good solvent, oil, water and hydraulic fluid resistance, good compression set, abrasion resistance and tensile strength. Nitrile should not be used in highly polar solvents such as acetone and MEK ozone chlorinated hydrocarbons and nitro hydrocarbons."

[ElaineB]

I've got both a snork and the point seals, but I don't have a micrometer. I'd be interested if you find out the answer to this.

 

ElaineB

[Daniel Shih]

Just for confirmation, in case you haven't seen it on Pentrace, David Nishimura writes about the material of O-rings:

 

"As for the gasket material, I believe Nathan uses Buna, whereas the ones we sell are Viton."

[Gerry]

I took a set of measurements from a snork I have - hope that they are what you are looking for...

 

Tube - 1.58mm / 0.062" - 1/16"

Recess - 3.96mm / 0.156" - 5/32" - note: this is difficult to measure accurately.

try [1.5mm x 4mm]?

 

I would expect that the ID of the o-ring to be a little less than the tube to ensure a snug fit. Don't know what would be the best for the recess, perhaps a little larger? If you go larger on the OD, and smaller on the ID, remember that the the effects tend to add, so it might get a little tight.

 

I have a few of Fr. Terry's gaskets, and they measure 4.5mm / 0.178" OD and 1.5mm / 0.058" ID which is pretty close to 1/16"ID - 3/16" OD.

 

I have a lot of difficulty in getting that o-ring into the recess though. Perhaps a firm fit is desired to make the ring seal. Personally, I'd like to see 1.5mm x 4.0mm as the point seal dimensions myself.

 

 

Gerry

 

[Edited to add the fractional equivalent of the recess - 5/32"]

Edited July 29, 2005 by Gerry

[KendallJ]

Gery -

 

It looks like the Father Terry O-ring may be the best you can get off the shelf. Here's the deal:

 

Size specified by WxID (OD is just a reference)

 

From measurements of the tube and compartment, we have: 3/64 x 1/16 (OD 5/32) or 1.2mmx1.6mm (OD 4mm)

 

Available sizes in english (actual dimensions run a hair smaller)

-003 (Fr Terry) is 1/16x1/16 (3/16OD) tight on compartment, fine on tube

-002 3/64x3/64 tight on tube, loose on compartment

 

Metric is worse

1mmx1.5mm (3.5OD) tight on tube loose on compartment

1mmx1.8mm (3.8OD) loose on tube, loose on compartment

 

I think you'd want something that is tight on the compartment and fine or a little loose on the tube. The Fr Terry Oring is the only one that fits this criteria close enough. Thoughts?

[John]

Personally, for the point seal I would stick with a gasket of the same design as the Sheaffer original, which, of course, is not an O ring.

[Gerry]

John, I'm interested - what is the original?

 

Gerry

[John]

The cross-section is rectangularly with an, again, rectangular cross sectioned "moat" in each face.

[Gerry]

John,

 

They are a little hard to visualize from the description. Are they available from any supplier?

 

Gerry

[John]

Martin Ferguson

parker51@comcast.net