Part# 04-02266
MFR Model# MS28778-10
DescriptionTube ODPart No.
MS28778 Tube Fitting Boss Gasket5/8MS28778-10


Straight-thread tube fitting boss gaskets are used to provide a seal between straight-thread fittings, such as AN815, and ports of instruments with female straight threads instead of the more common female tapered pipe threads.
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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: MS28778-12 says its 3/4 on your site. Other sites show closer to 1, and that is the correct size for my application Can you verify the actual size? Original P/N is AN6290-12.

It is closer to 1". The 3/4 is in reference to what size AN fitting it is used with. An AN815-12 for example is a 3/4 fitting but measures almost an inch in diameter.

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