C89833

C89833 is a lead-free red brass alloy also known as copper-bismuth alloy or UNS C89833. It contains a high percentage of copper (86-91%) with significant tin (4-6%) and zinc (2-6%) additions, plus bismuth (1.7-2.7%) as a lead substitute to enhance machinability and corrosion resistance.

Chemical Composition (Typical ranges)

• Copper (Cu): 86.0% – 91.0%

• Tin (Sn): 4.0% – 6.0%

• Zinc (Zn): 2.0% – 6.0%

• Bismuth (Bi): 1.7% – 2.7%

• Nickel (Ni): Up to 1.0%

• Iron (Fe): Up to 0.3%

• Lead (Pb): Max 0.09%

• Others (P, Al, Sb, S, Si): Trace amounts

Mechanical Properties (as sand cast, typical)

• Tensile Strength: ~30 ksi (207 MPa)

• Yield Strength (0.5% offset): ~14 ksi (97 MPa)

• Elongation: ~6%

• Brinell Hardness: ~60 HB

• Impact Resistance (Izod): ~12 ft-lbs

Physical and Thermal Properties

• Melting Point: Solidus 1454 °F (790 °C), Liquidus 1877 °F (1025 °C)

• Density: 0.317 lb/in³ (8.78 g/cm³)

• Electrical Conductivity: 17.8% IACS at 68 °F

• Thermal Conductivity: 41 BTU/(ft·hr·ft²·°F) at 68 °F

• Coefficient of Thermal Expansion: 13 × 10⁻⁶ /°F (68 – 392 °F)

Fabrication & Applications

• Excellent machinability with a rating of 81 (higher than many leaded brasses)

• Good soldering and brazing properties

• Not recommended for oxyacetylene welding or arc welding processes

• Used as a lead-free alternative to leaded red brass alloys (like C83600)

• Commonly employed in water meters, valves, pump components, plumbing fittings, and small gears

• Provides corrosion resistance, good wear properties, and moderate mechanical strength