Faying surface

A faying surface is one of the surfaces that are in contact at a joint.

Faying surfaces may be connected to each other by bolts or rivets, or by adhesives or welding or by soldering. An example would be steel pipe flanges. The connected ends of the flanges would be faying surfaces then.

http://www.eaa1000.av.org/technicl/corrosion/faysurf.htm

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