O-ring Diameter on FX Schematics

[jbravo103]

Can anyone confirm if the FX schematics are referring to I.D. or O.D. for o-ring sizes? It seems in some cases they are listing O.D., and in other cases they are listing I.D.

Case 1
The Impact barrel liner o-ring (A6) is shown as 13.95 x 2.62 mm. I believe the 13.95 is O.D. and 2.62 is cross section. I.D. would be 13.95 - (2 x 2.62) = 8.71 mm. If we assumed 13.95 mm was the I.D. then that would be way too big for the liner.

Case 2
The o-ring on the AMP regulator set screw (Part No. 19731, C38). It is listed as 2x1, NBR 90. Using the same logic above, the I.D. of that o-ring would be 0, which can't be right so I must assume the 2 mm is the I.D. and 1 mm is the C.S. In this case the O.D. would be 4 mm.

 

[Enkey]

Hi

Do not trust the measurements, some do not match, better take the measurement with a caliper

Regards

Enkey 

 

[Centercut]

ID x CS

Inner diameter and oring cross section (how thick is the rubber). 
Most oring stores sell as CS x ID... they are usually metric but FX slides in some Imperial from time to time

Mike

 

[jbravo103]

I agree Enkey, best to confirm with a calipers since there seems to be inconsistencies on the schematics.

BTW - I was planning to order parts from FX USA to rebuild my AMP regulator. They wanted $140 for new set of Belville washers, WTF. Are those hand made made from platinum in the Swiss alps and shipped to FX on a golden carriage? I’ve never witnessed such highway robbery.

 

[jbravo103]

Ok, I need to submit a correction. The spring washers are $12 for a set of 12. FX realized they had quoted me wrong. Back to reality.

 

[30harry]

ID x CS

Inner diameter and oring cross section (how thick is the rubber). 
Most oring stores sell as CS x ID... they are usually metric but FX slides in some Imperial from time to time

Mike

Yes, just discovered that on the crown. They use metric on EVERYTHING until they can't find a metric to fit and then it's back to SAE/Imperial. 1.27mm equals .05 inch.