About 630|Nickel aluminum bronze (81% copper, 10% aluminum, 5% nickel, 4% iron). One of the highest-strength copper alloys available. Exceptional corrosion resistance in seawater and excellent resistance to cavitation erosion. This is ship propeller material, pump impeller material, and heavy-duty valve seat material. Strength approaches medium-carbon steel levels. Machines like a tough alloy steel — needs rigid setups, sharp carbide, moderate speeds, and aggressive feeds. Do not let the tool rub. Used in marine, oil and gas, and power generation applications. Compare to
C954 (slightly lower strength, more common) and
614 (lower aluminum, lower strength, easier to machine).
