Copper Alloy C69710-O61
Heat-treated state
UNS C69710
O61 = annealed
Choose when maximum ductility for bending, upsetting or cold heading is required.
Values for the O61 condition
Other C69710 tempers and conditions
C69710 is listed in 6 conditions; see the grade overview at C69710.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O61This page Annealed | Choose when maximum ductility for bending, upsetting or cold heading is required. | 170 | 400 | 35 | 95 HB | 6.9 % IACS |
M30Default As hot extruded | Standard stock condition for extruded silicon-brass rod destined for screw-machine parts and forging blanks. | 215 | 450 | 25 | 120 HB | 6.7 % IACS |
Quarter hard | Light draw for improved straightness, size tolerance and surface finish with retained bendability. | 300 | 500 | 18 | 140 HB | 6.7 % IACS |
Drawn and stress-relieved | Use when residual stresses from drawing must be removed to avoid distortion after machining. | 360 | 530 | 14 | 150 HB | 6.5 % IACS |
Half hard | Most common drawn condition — best combination of strength, chip control and dimensional accuracy for automatic machining. | 380 | 550 | 12 | 160 HB | — |
Full hard | Heavy draw for maximum strength and wear resistance in shafts, pins and fasteners where little forming follows. | 480 | 620 | 8 | 185 HB | 6.5 % IACS |
What is C69710-O61?
C69710-O61 is C69710 heat treated to O61 — choose when maximum ductility for bending, upsetting or cold heading is required. C69710-O61 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 62% of copper alloy grades. Elongation at break is 35% and the elastic modulus is 103 GPa (14.9 Msi). C69710-O61 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F). M30 is the default condition FabDigit quotes; O61 is available on request or by drawing note.
Advantages
- Good corrosion resistance — 72/100, better than 84% of copper alloy grades
- Ductile — tolerates forming and impact — 35%, better than 80% of copper alloy grades
- Easy to machine — 70/100, better than 78% of copper alloy grades
Limitations
- Poor heat conductor — 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 91% of copper alloy grades
- Low electrical conductivity — 6.9 % IACS, worse than 88% of copper alloy grades
C69710-O61 properties
Typical room-temperature values for C69710-O61; 20 are specific to this condition. Other listed values are C69710 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C69710-O61 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F).
Mechanical13
C69710-O61 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 62% of copper alloy grades. Elongation at break is 35% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C69710-O61 is rated for continuous service to 200°C (392 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), worse than 91% of copper alloy grades. Thermal expansion is 20.2 µm/m·K (11.2 µin/in·°F).
Electrical3
C69710-O61 conducts electricity at 6.9 % IACS, worse than 88% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 84% of copper alloy grades.
Sustainability4
Producing a kilogram of C69710-O61 takes about 60 MJ of energy and emits 3.8 kg of CO₂ — more than 69% of copper alloy grades. Typical recycled content is 50%.
Manufacturability7
C69710-O61's machinability is very good (70/100, better than 78% of copper alloy grades); weldability fair (35/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C69710-O61
Is C69710 easy to machine?
Machines like a free-cutting brass at ~80% of C36000 — use sharp positive-rake carbide or HSS, high speed, light feeds; chips are short but tougher than 60/40 leaded brass.
Can C69710 be welded?
Fusion welding is not recommended (lead causes hot cracking); join by silver brazing, soft soldering or mechanical means.
Can C69710 be formed, bent or molded?
Excellent hot extrudability and forgeability at 650–750 °C; cold forming limited — anneal ~500–550 °C between heavy draws or bends.
What surface finishes work on C69710?
Buffs to a bright gold-tone finish; accepts nickel/chrome plating and clear lacquer or benzotriazole passivation; anodizing not applicable.
C69710 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 |
|---|---|---|
| Cu | 75 – 80 | 77.5 |
| Siforms silicide/κ phase, suppresses dezincification | 2.7 – 3.4 | 3 |
| Pbfree-machining addition | 0.8 – 1.5 | 1 |
| Feimpurity limit | ≤ 0.2 | — |
| Znbalance, nominally ~18–20% | balance | — |
C69710-O61 — frequently asked
What is C69710-O61 used for?
C69710-O61 is typically used for extruded rod for machined fittings, valve components and plumbing hardware. In short: best-machining silicon brass; rod and bar stock grade; low conductivity, 6.7 % IACS.
What is the yield strength of C69710-O61?
C69710-O61 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 62% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C69710-O61 easy to machine?
Yes — machinability is rated very good (70/100, better than 78% of copper alloy grades). Machines like a free-cutting brass at ~80% of C36000 — use sharp positive-rake carbide or HSS, high speed, light feeds; chips are short but tougher than 60/40 leaded brass.
Can C69710-O61 be welded?
With care — weldability is rated fair (35/100). Fusion welding is not recommended (lead causes hot cracking); join by silver brazing, soft soldering or mechanical means.
What surface finishes work on C69710-O61?
Buffs to a bright gold-tone finish; accepts nickel/chrome plating and clear lacquer or benzotriazole passivation; anodizing not applicable.
Can C69710-O61 be formed, bent or molded?
Excellent hot extrudability and forgeability at 650–750 °C; cold forming limited — anneal ~500–550 °C between heavy draws or bends.
What is the maximum service temperature of C69710-O61?
C69710-O61 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C69710-M30 and C69710-H04?
M30 is the default condition — standard stock condition for extruded silicon-brass rod destined for screw-machine parts and forging blanks. H04: heavy draw for maximum strength and wear resistance in shafts, pins and fasteners where little forming follows. Yield strength is 215 MPa in M30 versus 480 MPa in H04.
Sources
- ASTM B928 / UNS C697xx alloy registration (Copper Development Association) — CDA / ASTM (2020)
- CDA Alloy Database — C69700 silicon leaded brass properties — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion of Copper and Copper Alloys — ASM International (2005)
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.