Brass C260 properties
Summary
Section titled “Summary”C260 brass (UNS C26000) is a copper-zinc alloy with approximately 70 % copper and 30 % zinc. Known as cartridge brass, it exhibits the highest ductility of the yellow brass family and stands out for its excellent cold formability, good corrosion resistance, and golden appearance. It is widely used in the manufacture of cartridges, architectural components, musical instruments, and plumbing applications.
Chemical composition
Section titled “Chemical composition”| Element | Content (%) |
|---|---|
| Copper (Cu) | 68.5 – 71.5 |
| Zinc (Zn) | Balance (approx. 28.5 – 31.5) |
| Lead (Pb) | ≤ 0.070 |
| Iron (Fe) | ≤ 0.050 |
| Other elements total | ≤ 0.15 |
Physical properties
Section titled “Physical properties”| Property | Metric | Imperial |
|---|---|---|
| Liquidus temperature | 954 °C | 1750 °F |
| Solidus temperature | 916 °C | 1680 °F |
| Density at 20 °C (68 °F) | 8.53 g/cm³ (8530 kg/m³) | 0.308 lb/in³ |
Mechanical properties by temper
Section titled “Mechanical properties by temper”| Temper | Tensile strength (MPa / ksi) | Yield strength (MPa / ksi) | Elongation in 75 mm (%) | Young modulus (GPa / ksi) |
|---|---|---|---|---|
| Annealed | 303 / 44 | 76 / 11 | 66 | 117 / 16 970 |
| Quarter-hard | 379 / 55 | 207 / 30 | 43 | 117 / 16 970 |
| Half-hard | 483 / 70 | 345 / 50 | 23 | 117 / 16 970 |
| Hard | 586 / 85 | 414 / 60 | 8 | 117 / 16 970 |
| Spring | 689 – 896 / 100 – 130 | 448 / 65 | 3 | 117 / 16 970 |
Poisson’s ratio: 0.34 for all tempers.
Thermal properties
Section titled “Thermal properties”| Property | Metric | Imperial |
|---|---|---|
| Coefficient of thermal expansion (20 – 300 °C) | 19.9 µm/m·°C | 11.1 µin/in·°F |
| Thermal conductivity at 20 °C (68 °F) | 120 W/m·K | 833 BTU·in/(h·ft²·°F) |
| Specific heat capacity (typical value) | 0.38 J/g·°C | 0.091 BTU/lb·°F |
Other designations
Section titled “Other designations”| Standard / System | Designation |
|---|---|
| UNS | C26000 |
| ASTM | B19, B36, B129, B134, B135, B569, B587 |
| SAE | J461, J463 |
| MIL | C-10375, S-22499, T-20219 |
| EN (Europe) | CuZn30 (CW505L) / 2.0265 |
| BS (United Kingdom) | CZ106 |
| AFNOR (France) | CuZn30 |
| JIS (Japan) | C2600 |
| ISO | CuZn30 |
Fabrication and heat treatment
Section titled “Fabrication and heat treatment”- Annealing: heat between 427 and 760 °C (800 – 1400 °F), followed by slow cooling to obtain maximum softness and ductility.
- Cold working: excellent suitability for deep drawing, bending, stamping, and coining. Work hardening is controlled with intermediate anneals.
- Hot working: forging is performed between 650 and 800 °C (1200 – 1470 °F). It is also suitable for extrusion and hot rolling.
- Welding: brazing, soldering, and oxyacetylene welding processes are recommended. Resistance welding is not advised.
- Machining: its machinability is moderate (machinability index ~20 % relative to free-cutting brass C360). Use of sharp tools and coolant is advisable in complex operations.
- Finishing: accepts all types of electroplated coatings (nickel, chrome, silver, gold) and protective lacquers.
Applications by industry
Section titled “Applications by industry”- Ammunition and defense: cartridge cases and ammunition (hence the name “cartridge brass”).
- Architecture and decoration: door handles, handrails, decorative frames, lighting fixtures, commemorative plaques.
- Plumbing and gas fitting: threaded fittings, valves, connections, faucets.
- Electricity and electronics: connection terminals, stamped connectors, low-load contacts.
- Automotive and HVAC: radiators, heater cores, coolant tanks, thermostats.
- Musical instruments: trumpet bodies, trombones, saxophones, cymbals, and bells.
- Consumer goods: zippers, jewelry, medals, engraved plates, lighters.
Comparison with similar materials
Section titled “Comparison with similar materials”| Alloy | Cu (% approx.) | Zn (% approx.) | Tensile strength (annealed) | Elongation (annealed) | Key characteristics | Typical applications |
|---|---|---|---|---|---|---|
| C260 (Cartridge brass) | 70 | 30 | 303 MPa | 66 % | Maximum ductility in the yellow series; excellent for deep drawing | Cartridges, stamped parts, musical instruments |
| C268 (Yellow brass) | 65 | 35 | 293 MPa | 53 % | Good ductility, lower cost due to lower copper content | Costume jewelry, writing instruments, plumbing components |
| C280 (Muntz metal) | 60 | 40 | 358 MPa | 40 % | Higher mechanical strength, good suitability for hot working | Ship hull plates, heat exchanger heads, forged parts |
| C230 (Red brass) | 85 | 15 | 283 MPa | 48 % | Superior corrosion resistance, reddish color | Water pipes, condensers, marine architectural applications |
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”What is the maximum tensile strength of C260 brass?
Section titled “What is the maximum tensile strength of C260 brass?”The maximum value reaches 896 MPa (130 ksi) in spring temper, although in the annealed condition it is only 303 MPa.
At what temperature does C260 brass melt?
Section titled “At what temperature does C260 brass melt?”Melting begins at 916 °C (solidus) and completes at 954 °C (liquidus), corresponding to a melting range of 38 °C.
What is the exact density of this alloy?
Section titled “What is the exact density of this alloy?”At 20 °C the density is 8.53 g/cm³, i.e., 8530 kg/m³ in SI units.
What elongation does C260 exhibit in the annealed condition?
Section titled “What elongation does C260 exhibit in the annealed condition?”It reaches an elongation of 66 % in a 75 mm gauge length, demonstrating its exceptional plastic deformation capacity.
What is the thermal conductivity of C260 brass?
Section titled “What is the thermal conductivity of C260 brass?”Its thermal conductivity is 120 W/m·K at 20 °C, facilitating heat dissipation in electrical and thermal components.
Which ASTM standard covers C260 brass sheet?
Section titled “Which ASTM standard covers C260 brass sheet?”The main standard is ASTM B36/B36M, which specifies requirements for cartridge brass sheet.
Technical standards
Section titled “Technical standards”- ASTM B19: Seamless brass tubes.
- ASTM B36/B36M: Plate, sheet, and strip of cartridge brass.
- ASTM B129: Seamless brass wire for cartridges.
- ASTM B134: Brass wire (C26000) for springs.
- ASTM B135: Seamless brass tube (C26000) for heat exchangers.
- ASTM B569: Cartridge brass strip for plumbing fixtures.
- ASTM B587: Rods and shapes of cartridge brass.
- SAE J461: Classification of nonferrous metals and alloys.
- SAE J463: Physical properties of metals.
- Military specifications: MIL C-10375, MIL S-22499, MIL T-20219.
References
Section titled “References”- azom.com: https://www.azom.com/article.aspx?ArticleID=6341
- engineeringtoolbox.com: https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html
- steelnumber.com: https://www.steelnumber.com/en/equivalent_alloy_eu.php?zname_id=1251