About 673|Manganese bronze (58.5% copper, 39% zinc, 1.4% iron, 1% tin, 0.1% manganese). Despite the name, this is essentially a high-strength brass with minor additions. Very high tensile strength for a copper alloy (65–80 KSI). Used for heavy-duty gears, large propeller shafts, valve stems, and structural marine applications. Machines adequately — better than silicon bronze, worse than leaded brass. The iron content gives it wear resistance beyond what plain brass offers. Compare to 464 naval brass (lower strength, better dezincification resistance) and
630 nickel aluminum bronze (higher strength, better corrosion resistance, harder to machine).
