LeRhone propeller ID help!

[msprior01]

Greetings forum, I have a propeller that I'm trying to figure out the aircraft and age. It is 8ft mahogany and here are the engravings: LEHRONE S.C. 76199 UNION PRO NO. 004 DRAWING NO. 18 1X8 on the side of the hub: 0640 E22 8 FT. DIA. ?17P No decals, no metal cladding, square tips and 2/3 of the blades are covered in original cloth. Any assistance would be greatly appreciated. Thanks, Scott

[Dave]

It certainly sounds like an American manufactured propeller made for one of the LeRhone powered aircraft that found their way to the U.S. after WW1 for a variety of testing, training, etc. The "S.C." typically stands for Signal Corps, and the number following it (76199) is likely a serial number, implying (based on other props with lower numbers) that it was probably made some time after WW1.

Propellers were made to fit specific engines, and the diameter and pitch was usually specified for specific aircraft, but there is considerable overlap in that, so frequently it's impossible to know what aircraft it was intended for or used on.

I'm not familiar with the manufacturer, which I presume is Union Pro-something.

Can you post a picture?