Hamilton Standard propeller blade markings

[loakleyi]

Can anyone help be determine the correct way to mark a 1944 Hamilton Standard 2B20 propeller blade? Specifically looking for what DWG referred to. Is it the Blade drawing or drawing for something s else. Is the part number on the Hamilton Standard picture, the part number for the blade, hub, or something else? Cannot find and Drawings for the 2B20. First Picture is for a McCauley prop. Additionally what does "A.C.R." refer to in the third photo?

 

[Wurger]

Welcome to the site.

As memo serves, the DWG number should be stamped somewhere at the prop blade root. Have you checked on that? Also the number "2B20" is a hub prop model and is a part of the prop number only. The prop balde types that could fit the hub are the different matter IIRC.

2B20 =
2 - a two balde counterweight prop type
B - the prop balde shank size
20 - the prop shaft spline size.

 

[Geoffrey Sinclair]

Propeller description systems (From War Production Board Report). Hamilton Standard Hydraulic e.g. 12B20
1 First revision
2 Number of blades
B Blade shank size
20 Engine shaft size

Hamilton Standard 2-B-20, controllable, 2 blade, dural, already in production before 1940, phased out in 1944/5, used on AT-8, 9, 10, 19, UC-78

As of 16 March 1942, 2-B-20 with blade design 6135A-15, 7 feet 9 inches, on AT-8 and AT-10, same combination but 7 feet 7 inches on AT-17 (Wood?), 2-B-20 with blade design 6135A-6, 8 feet 6 inches on AT-17

 

[Michael Hope]

Here is the required blade markings per EO 15-30A-3 from about 1952.
There are three different blade drawing numbers/models possible for the 2B20 propeller are "6109A-?", "6135A-?", and "6241A-?". The"?" is the blade cutoff, the cutoff depends on the aircraft that the blade is installed on.

 

[loakleyi]

Here is the required blade markings per EO 15-30A-3 from about 1952.
There are three different blade drawing numbers/models possible for the 2B20 propeller are "6109A-?", "6135A-?", and "6241A-?". The"?" is the blade cutoff, the cutoff depends on the aircraft that the blade is installed on.

View attachment 740500

Very helpful. Thank you very much.

 

[Barrett]

This thread reminds me of what I've long suspected:
Nobody knows everything
but
Somebody knows everything about something!
Keep it up, guys.

 

[Simon Thomas]

A.C. is Air Corps Acquisition Number
Similar example here: enginehistory.org :: View topic - How to identify the Maker of a WWII Solid Aluminum Propeller

 

[SaparotRob]

This thread reminds me of what I've long suspected:
Nobody knows everything

Have to disagree. My wife knows everything.

 

[GregP]

You might have her write it all down sometime ... you know, for reference.