my fathers prop

It's most likely designed for the Felixstowe F5L, based on the stampings. The "SE 5111" is the drawing number, or blueprint number, that describes the shape of the propeller, with "SE" referring to "Steam Engineering", the Navy department that was in charge of procuring propellers for the Navy in the late teens. The bolt holes should be 8" apart across the longest distance across the hub, which is the size of the hub for a Liberty engine.

Many propellers look the same, but are distinctly different in their design and applications. There were thousands of different designs by the end of WW1.

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