This is the serial number given to the prop by Airco, the Aircraft Manufacturing Company. Geoffery de Havilland was the chief designer and designed the DH4 bomber. AMC made some props for its own aircraft but most were made under government contract, principally by Maple but also by others such as the Integral Propeller Co.
better pics of dh4 prop. has been cut in half and put back together with newly made bracket to resemble engine mount.
i am presuming its actually a ww1 prop.
Bob
The G number is a batch number, here 299, and N1 indicates its the first in a batch of 100. It dates from late 1917.
Your data decodes as;
P3640 Pitch in mm
D3048 Diameter in mm
DRG 2442 The drawing number. It's an Air Board design and the full number would be written as AB2442
RAF3A The engine, a type 3A of 200hp designed by the Royal Aircraft Factory
DE H4 The aircraft type; the DH4 in modern notation. Designed by Geoffery de Havilland, the designer at the Aircraft Manufacturing Company, known as AIRCO
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