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.
Quality part !!
O-RINGS AN6227B-7 MS28775-012
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
--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.
Mil Spec...are there any better?
This is the o-ring that keeps the hydraulic oil in your brake calipers. Keep plenty on hand. Pay either 87 cents for this one or $22.70 apiece for the ones from Cleveland.
The MS28775-xxx / AN6227B-xx are the hydraulic fluid resistant O-Rings that I use in the brake system of my Beech 19A. Each O-Ring comes in its own separate well marked bag - hence they store / age well and you know that what they are and that they are new.
I have not utilized the O rings as of yet, but they look good and will replace old/worn out O rings in the engine baffles.
They are round, flexible, and new. They prevent hydraulic fluid from leaking better then old, stiff, oval ones.
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.
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.
These are POLYTETRAFLUOROETHYLENE per the mil spec.
15 years per the cert.