Parts Wanted O rings for OS

[FloridaScaleBoater]

Yeh, I have a set from a new needle.
You measure & I'll measure to see what we come up with.

I'm coming up with some numbers that are not in McMaster Carr??
I'm getting:
ID 1.80MM .070-.071"
OD 3.15-3.16MM .125"
X-section, too small for me to measure
I'm seeing nothing In McM Carr
Maybe I should try measuring the groove that it sits in??
And the OD while in the groove??
Any direction folks.

 

[dave roach]

Let me get you guys the right part no for the orings and if you need some i can get them.

 

[FloridaScaleBoater]

Let me get you guys the right part no for the orings and if you need some i can get them.

That would be great Dave.
I have a butt load of these needles and have never replaced any of the O-Rings in them (10-15) plus years.
And one of my boats is showing symptoms of an air leak somewhere.

 

[dave roach]

I will give you guys the answer in the morning Working.

Thanks Dave

 

[dave roach]

I contacted my suppler and he is out of them and i'am just weighting for a phone call from him.the oring john is talking about is for the Stu Barr needles.

 

[John Beardslee]

I contacted my suppler and he is out of them and i'am just weighting for a phone call from him.the oring john is talking about is for the Stu Barr needles.

The OS o-ring appears to be 1m x 2m x 1m.
A friend ordered the from MMC with the pn Grim provided, catalog shows 1m x 3m x 1m but the package shows a different pn and the ID is not 3m so MMC has a problem. He’s going to contact MMC. Meanwhile we measured his last OS spare and we think the ID should be 2mm.

 

[John Beardslee]

I contacted my suppler and he is out of them and i'am just weighting for a phone call from him.the oring john is talking about is for the Stu Barr needles.

The Bob Violet and Stu Barr use the 1/16” x 3/16” x 1/16” size o-ring

 

[John Beardslee]

Update on metric o-rings. If you go to the Oring store website you’ll find metric orings with a thinkness lesser than the 1mm minimum thickness offered by MMC.

 

[John Beardslee]

After checking an OS needle valve o-ring using a digital caliperI conclude the size to be: .5mm x 2mm x .5mm
(Note: metric O-rings are defined by their cross section and the I.D.) If anyone has access to a more refined measurement process jump in. This size is currently back ordered at the O-ring Store, I haven’t extended a search beyond that point.

 

[dave roach]

Ok Guys
Her is the size of the orings for the OS vaule1mm x .5 and i have 100 orings coming in .Let me know if you what some.

Thanks
Dave

 

[Wasted wages]

After checking an OS needle valve o-ring using a digital caliperI conclude the size to be: .5mm x 2mm x .5mm
(Note: metric O-rings are defined by their cross section and the I.D.) If anyone has access to a more refined measurement process jump in. This size is currently back ordered at the O-ring Store, I haven’t extended a search beyond that point.

Ok Guys
Her is the size of the orings for the OS vaule1mm x .5 and i have 100 orings coming in .Let me know if you what some.

Thanks
Dave

So which is it ???

1mm or 2mm ?

And how about a picture of an actual valve or O-ring so we can see if y’all are even measuring the same one ?

 

[John Beardslee]

So which is it ???

1mm or 2mm ?

And how about a picture of an actual valve or O-ring so we can see if y’all are even measuring the same one ?

Here’s a few pics, I will try to give more details later, on my way to appointments.

 

[Terry Keeley]

A buddy looked at the OS needle and o-rings with his optical comparator, here's what he came up with. The two on the right are the aftermarket I got that are nominal .055 x .031.

Dave, the ones I got from you are 0.60 x .030".

I'm quite sure they are proprietary, the aftermarket ones do fit but are a little tight so I massage the needle a bit for them.

Also, standard Nitrile isn't rated very good for nitro, EP holds up much better but don't use petroleum based lube to assemble them!

 

[John Beardslee]

A buddy looked at the OS needle and o-rings with his optical comparator, here's what he came up with. The two on the right are the aftermarket I got that are nominal .055 x .031.

Dave, the ones I got from you are 0.60 x .030".

I'm quite sure they are proprietary, the aftermarket ones I got do fit but are a little tight so I massage the needle a bit for them.

Also, standard Nitrile isn't rated very good for nitro, EP holds up much better.


View attachment 327770

Hey T, the sketch appears to be in SAE sizes, right? Something seems off compared to an actual OS replacement.
John

 

[Terry Keeley]

Hey T, the sketch appears to be in SAE sizes, right? Something seems off compared to an actual OS replacement.
John

Ya, that's why I was saying I don't think they're "nominal" sized, either SAE or metric.

OS OEM is what my toolmaker buddy measured on far left, you might find something closer than I ended up with from the supplier I used:

https://www.applerubber.com/products/microrings/

The cross section is so small the fit is critical to be "right". I also smooth & polish the ID of the body where the needle enters, there's a lip there that's great at tearing o-rings.

Also do this and it will repeat very well:

https://www.intlwaters.com/threads/simple-trick-to-improve-the-os-needle.74861/#comment-727234