Copper Alloy C50500-O60
Temper
UNS C50500 · ASTM B103
O60 = soft annealed
Choose for deep drawing, severe forming or when maximum ductility and conductivity are needed.
Values for the O60 condition
Other C50500 tempers and conditions
C50500 is listed in 8 conditions; see the grade overview at C50500.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O60This page Soft annealed | Choose for deep drawing, severe forming or when maximum ductility and conductivity are needed. | 97 | 276 | 48 | 60 HB | 50 % IACS |
Quarter hard | Choose when moderate forming is still required but annealed strength is insufficient. | 240 | 310 | 25 | 80 HB | 48 % IACS |
Half hard | General-purpose stamping temper balancing bend formability and spring strength. | 290 | 345 | 12 | 95 HB | 48 % IACS |
Half hard, stress-relieved | Choose when improved bend performance and stress-relaxation resistance are needed at half-hard strength. | 310 | 360 | 14 | 100 HB | 50 % IACS |
H04Default Full hard | Most commonly stocked strip temper for connectors, contacts and light springs. | 345 | 380 | 6 | 110 HB | 48 % IACS |
Extra hard | Choose for flat springs and contacts needing higher yield with minimal forming. | 380 | 415 | 4 | 125 HB | 47 % IACS |
Spring hard | Spring temper for flat springs, washers and contact fingers with good relaxation resistance. | 415 | 450 | 3 | 135 HB | 47 % IACS |
Extra spring hard | Maximum cold-worked strength for flat spring stock; almost no bendability across grain. | 435 | 470 | 3 | 140 HB | 47 % IACS |
What is C50500-O60?
C50500-O60 is C50500 in the O60 temper — choose for deep drawing, severe forming or when maximum ductility and conductivity are needed. C50500-O60 has a yield strength of 97 MPa (14.1 ksi) and a tensile strength of 276 MPa (40 ksi) — weaker than 87% of copper alloy grades. Elongation at break is 48% and the elastic modulus is 117 GPa (17 Msi). C50500-O60 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,035°C (1,895 °F). H04 is the default condition FabDigit quotes; O60 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 48%, better than 97% of copper alloy grades
- Forms and bends easily — 95/100, better than 94% of copper alloy grades
- Conducts heat well — 215 W/m·K (124.2 BTU/hr·ft·°F), better than 80% of copper alloy grades
- High electrical conductivity — 50 % IACS, better than 79% of copper alloy grades
Limitations
- Low strength — 97 MPa (14.1 ksi), worse than 87% of copper alloy grades
- Difficult to machine — 25/100, worse than 86% of copper alloy grades
C50500-O60 properties
Typical room-temperature values for C50500-O60; 13 are specific to this condition. Other listed values are C50500 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C50500-O60 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,035°C (1,895 °F).
Mechanical12
C50500-O60 has a yield strength of 97 MPa (14.1 ksi) and a tensile strength of 276 MPa (40 ksi) — weaker than 87% of copper alloy grades. Elongation at break is 48% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
C50500-O60 is rated for continuous service to 250°C (482 °F). It conducts heat at 215 W/m·K (124.2 BTU/hr·ft·°F), better than 80% of copper alloy grades. Thermal expansion is 17.8 µm/m·K (9.89 µin/in·°F).
Electrical3
C50500-O60 conducts electricity at 50 % IACS, better than 79% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C50500-O60 takes about 57 MJ of energy and emits 3.7 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C50500-O60's machinability is poor (25/100, worse than 86% of copper alloy grades); weldability good (55/100); formability excellent (95/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C50500-O60
Is C50500 easy to machine?
Gummy and low rated (~20% of free-cutting brass); use sharp positive-rake tools, high speed, light feed and generous coolant, or specify a leaded grade for screw-machine work.
Can C50500 be welded?
GTAW/GMAW with phosphor-bronze filler is workable; resistance welding is poor due to high conductivity, and soldering/brazing is the preferred joining route.
Can C50500 be formed, bent or molded?
Excellent cold formability in O60/H01; H04 and harder tempers need generous bend radii and preferably bending with the grain, with interstage annealing near 480–650 °C.
What surface finishes work on C50500?
Not anodizable; takes tin, nickel, silver and gold plating readily and polishes to a bright bronze finish — passivate or lacquer to limit tarnish.
C50500 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Sn | 1 – 1.7 | 1.3 |
| Pdeoxidizer, adds strength | 0.03 – 0.35 | 0.2 |
| Fe | ≤ 0.05 | — |
| Pb | ≤ 0.05 | — |
| Zn | ≤ 0.3 | — |
| CuCu + Ag, remainder | ≥ 98.7 (balance) | — |
C50500-O60 — frequently asked
What is C50500-O60 used for?
C50500-O60 is typically used for electrical connectors, springs, washers and cable shielding. In short: highest-conductivity phosphor bronze; 48 % IACS spring alloy; good cold formability.
What is the yield strength of C50500-O60?
C50500-O60 has a typical yield strength of 97 MPa (14.1 ksi) and a tensile strength of 276 MPa (40 ksi) — weaker than 87% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C50500-O60 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 86% of copper alloy grades). Gummy and low rated (~20% of free-cutting brass); use sharp positive-rake tools, high speed, light feed and generous coolant, or specify a leaded grade for screw-machine work.
Can C50500-O60 be welded?
Yes — weldability is rated good (55/100). GTAW/GMAW with phosphor-bronze filler is workable; resistance welding is poor due to high conductivity, and soldering/brazing is the preferred joining route.
What surface finishes work on C50500-O60?
Not anodizable; takes tin, nickel, silver and gold plating readily and polishes to a bright bronze finish — passivate or lacquer to limit tarnish.
Can C50500-O60 be formed, bent or molded?
Excellent cold formability in O60/H01; H04 and harder tempers need generous bend radii and preferably bending with the grain, with interstage annealing near 480–650 °C.
What is the maximum service temperature of C50500-O60?
C50500-O60 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C50500-H04 and C50500-O60?
H04 is the default condition — most commonly stocked strip temper for connectors, contacts and light springs. O60: choose for deep drawing, severe forming or when maximum ductility and conductivity are needed. Yield strength is 345 MPa in H04 versus 97 MPa in O60.
Sources
- ASTM B103/B103M — Phosphor Bronze Plate, Sheet, Strip and Rolled Bar — ASTM International (2019)
- CDA Alloy Datasheet C50500 — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- GB/T 2059 / GB/T 2049 (QSn1.5-0.2) — SAC (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.