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O-RINGS AN6227B-23 MS28775-218

Part# AN6227B-23
MFR Model# MS28775-218
PNMS EquivalentWidthIDOD


O-rings give effective sealing over wide ranges of pressure, temperature, and movement, with the advantage of sealing pressure in both directions and reducing friction and wear on moving parts. The use of O-rings as gaskets or static seals permits metal-to-metal contact and allows almost unlimited pressures under extreme vibration.

All O-rings should be lubricated before installation and constant lubrication should be provided for running seals to avoid excessive wear. Avoid sharp edges, threads, and cross-drilled ports over or through which rings must be installed. AN6227B and AN6230B O-rings are manufactured to Spec. MIL-P 25732 for use in hydraulic systems using MIL-0-5606 hydraulic oils. MS28775 O-rings meet Spec. MIL-P- 5510A and are suitable for MIL-0-5606 hydraulic fluid at 160 F.


These riings worked perfectly. I had tried non-spec o-rings with disastrous results. Thank you AS&S!

Gus G Verified Purchase

O-RINGS AN6227B-23 MS28775-218

May 22, 2022

I keep several of these in my toolbox so they are readily available when changing out brake pads.

Paul A Verified Purchase

O-RINGS AN6227B-23 MS28775-218

March 5, 2022

William J Verified Purchase

O-RINGS AN6227B-23 MS28775-218

February 23, 2022


William T Verified Purchase

O-RINGS AN6227B-23 MS28775-218

January 29, 2022

Excellent product

Kenneth M Verified Purchase

O-RINGS AN6227B-23 MS28775-218

October 16, 2021

Ralph S Verified Purchase

O-RINGS AN6227B-23 MS28775-218

September 26, 2021

Douglas E Verified Purchase

O-RINGS AN6227B-23 MS28775-218

July 21, 2021

Correct O ring for P 28R brake cylinder

Dan V Verified Purchase

O-RINGS AN6227B-23 MS28775-218

May 27, 2021

Didnt have a part number and was surprised that your outstanding folks couldnt find it right off hand. Once I called back with the part number, no problem. And your phone folks are always fun to talk to. Ed

Ed W
May 12, 2021

--quick delivery, tracking, --individually packaged o rings, manufacture date and specs on each envelope. --i also ordered from another company, (original manufacture of the hydraulic swivel), to ensure product delivery during covid pandemic. i did not use the other product eventhough i paid for a faster priority delivery, and it arrived a day sooner, with ups, those rings were all in one bag and appeared to have been produced 9 years ago, and were more expensive. also a third possible source, a local hydraulic supply company wanted 6 times more money then aircraft spruce, which had to be shipped frim another state, for the same o rings, of unknow origin, quality and specs. i did not order those. --aircrat spruces product looked better and i had the confidence of manufacture date. --the o rings i replaced failed from age, not wear. the hydraulic swivel containing them was difficult to remove and install. they work well and i have the confidence they will last another 20 plus years. the original ones lasted 50 plus years.

March 16, 2021


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Can these O rings be used in fuel cells with 100LL fuel?

These o-rings, AN6227B series, are not fuel resistant. For fuel resistant o-rings, see the MS29513 series. MS29513 are aviation fuel resistant, but not resistant to automotive fuel. Search for MS29513 on our web site to find the page with the fuel resistant o-rings.

Q: Are the O-rings Butyl rubber?

These are POLYTETRAFLUOROETHYLENE per the mil spec.

Q: What is the shelf life of these o-rings?

15 years per the cert.

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