GPA PROPELLER MADE OF WHAT MATERIAL?

[James Hybicki]

WHAT WAS THE GPA PROPELLER MADE FROM. I HAVE THE OPPORTUNITY TO BUY A GPA BRASS PROPELLER MARKED WITH GPA4055 ON IT. THE GPA I HAD CAME WITH 2 STEEL (?) PROPELLERS. ANY POSITIVE INFORMATION? THE PARTS MANUAL DOES NOT TELL WHAT THE PART IS MADE OF.

ADVISE
JIM HYBICKI

[dukw45]

The original GPA prop I once owned appeared identical in composition to the one on my DUKW. They were both made by Michigan Wheel, and are either bronze or Nibral. I have always believed they are Nibral, but cannot recall the source of the info. Nibral, at least to me, is indistinguishable from bronze.

Jim Pepper

[Donovan]

My propellor that is stamped with the part number is steel. This may be an early versus late thing where the early GPAs had brass propellers and the late ones had steel.
Donovan.

[acmack]

Mine is steel but I have no idea if it was the original one.
BTW I have 3 series of stamped numbers on it. One is GPA and the part no. 4455. The second says Federated, I assume it's the manufacturers name Federal Steel.
The third, I can only make out some letters and numbers but don't know what it means. Is it the prop specs for pitch and size?