Re: "Brass props"

[green-thumbs]

"Bronze" and "Brass" do NOT tell you very much. For instance cartridge cases are made of cartridge brass…70% Copper and 30% Zinc. Tobin Bronze is 70% Copper and 30% Zinc and up
to 1% tin….your math and mine add up to 101% Go Figure.
Tobin Bronze was used for prop shaft on what were called cabin cruisers and also on
certain war time Canadian coins instead of nickle.
Alloys of Copper may be called Bronze, Brass or a trade name such as Muntz Metal. Foundry practice vary
so the exact composition of alloy will differ from lot to lot and as well as foundry to foundry.
Local brass foundry makes copper tubing using recycled metal…they try to keep lead content
below an allowed amount, but, that depends upon what they get from scrap yard.
Not much metal sourced from refinery so alloy will vary to some degree.
I expect Michigan Wheel is more interested in how well metal machines and holds up in use
rather than exact Chemical Analysis.
High prices paid for metal scrap resulted in a lot of old outboards going to junk yard.
I bought a few there.
Louis