1. Chemical Composition (Core Distinction)
2. Mechanical Properties
C61300 Mechanical Properties (Typical, Annealed State)
Tensile Strength: 380–520 MPa (55–75 ksi)
Yield Strength (0.2% offset): 170–240 MPa (25–35 ksi)
Brinell Hardness (HB): 100–140
Elongation (% in 50mm): 15–25%
Key Trait: Balanced strength and ductility; lower hardness due to lower Al/Fe content.
C61900 Mechanical Properties (Typical, Annealed State)
Tensile Strength: 550–700 MPa (80–100 ksi)
Yield Strength (0.2% offset): 275–380 MPa (40–55 ksi)
Brinell Hardness (HB): 150–200
Elongation (% in 50mm): 10–20%
Key Trait: Significantly higher strength and hardness; slightly reduced ductility due to higher Al/Fe/Ni content.
Cold-Worked/Heat-Treated State Differences
C61300: Cold working increases tensile strength to 600–750 MPa (87–109 ksi), but it is rarely heat-treated (limited strengthening potential).
C61900: Responds well to heat treatment (solutionizing + aging), with tensile strength reaching 750–900 MPa (109–130 ksi) - ideal for high-load applications.
3. Machinability
C61300: Higher lead content (2–4%) acts as a "lubricant" during machining, reducing tool wear and improving chip formation. It is classified as easily machinable (rating ~70–80 on the brass machinability scale, where free-cutting brass = 100). Suitable for high-volume precision machining (e.g., small gears, fasteners).
C61900: Lower lead content (0.8–1.5%) and higher hardness make it moderately machinable (rating ~40–50). It requires carbide tools, slower cutting speeds, and specialized coolants to avoid tool damage. Machinability is secondary to its strength and corrosion resistance.
4. Corrosion Resistance
C61300: Resists atmospheric corrosion, freshwater, and mild chemicals. The protective Al₂O₃ layer is thinner (lower Al content), so it is less suitable for seawater or concentrated corrosive media.
C61900: Higher Al, Fe, and Ni content forms a denser, more durable Al₂O₃ layer. It exhibits excellent resistance to seawater, marine biofouling, galvanic corrosion, and industrial chemicals (e.g., dilute acids, alkalis). Ideal for offshore and chemical processing applications.
5. Application Suitability
C61300 Applications
Precision machined parts (gears, bushings, valve stems, fasteners).
Automotive components (engine thrust washers, hydraulic fittings).
General industrial hardware (nuts, bolts, pump components for freshwater systems).
Food processing equipment (non-toxic, easily machined parts).
C61900 Applications
Marine engineering (propellers, shaft sleeves, hull fittings, offshore pipeline valves).
Heavy industrial machinery (high-load bearings, wear plates, crusher liners).
Chemical processing equipment (pump impellers, reactor fittings, acid-handling pipes).
Aerospace and defense components (structural parts requiring strength and corrosion resistance).
6. Cost and Availability
C61300: More widely available and cost-effective, thanks to lower alloying element content (especially Ni) and simpler manufacturing processes.
C61900: Higher cost due to higher concentrations of Al, Fe, and Ni. It is produced in specialized grades for high-performance applications and may have longer lead times.
