U. S. Propellers

[aungsut]

I'm trying to locate data on how to identify the marking on U. S. Propellers.

One is being offered on eBay with the following information:

44"
22088
S/N SS622

Does anyone have information on how to tell the pitch of U.S. Propellers?
Thanks,
John

[Dave]

It's a very commonly found UAV (drone) prop. I don't know the math involve in determining the pitch, but basically it involves measuring the angle of the blade at various distances then using trigonomety to calculate how that converts to a pitch distance, and there is a little fudge factor in the design as well.

See this diagram for clarification. Pitch is theoretical thread distance, similar to an ordinary wood screw.

[aungsut]

U.S. Propellers

Thanks Dave. I was hoping that U.S. Propellers used a marking system something like Sensenich where the length is followed by pitch information.
These drone propellers are similar in length to ones used on aircraft like mine (a BD-5) but I've been unable to tell the pitch which is critical to aircraft performance. U.S. Propellers were used frequently on BD-5s but that was many years ago. I know the pitch needed for my 5 but can't tell from their markings what the pitch is.
John