Copper Alloy C79600-O61
Heat-treated state
UNS C79600
O61 = annealed
Pick when maximum ductility for staking, riveting or secondary forming of machined parts is needed.
Values for the O61 condition
Other C79600 tempers and conditions
C79600 is listed in 6 conditions; see the grade overview at C79600.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O61This page Annealed | Pick when maximum ductility for staking, riveting or secondary forming of machined parts is needed. | 165 | 400 | 32 | 105 HB | 9 % IACS |
Annealed to 0.035 mm grain size | Grain-size-controlled anneal ordered when consistent deep-drawing or coining response is required after machining. | 175 | 415 | 30 | 105 HB | 8.5 % IACS |
As hot extruded | Standard mill condition for large-diameter rod and shapes before any drawing; best straightness-to-cost for rough machining. | 210 | 450 | 25 | 125 HB | 8.5 % IACS |
Quarter hard | Choose when parts still need some bending or swaging after machining but better chip control than annealed. | 310 | 480 | 22 | 140 HB | 8.2 % IACS |
H02Default Half hard | The default stocked rod condition — best balance of strength, straightness and free-cutting behaviour for screw-machine parts. | 400 | 550 | 15 | 160 HB | 8 % IACS |
Full hard | Use for small-diameter pins, shafts and springy parts where maximum strength and stiffness of the as-drawn bar matters. | 480 | 620 | 8 | 11 HRC | 7.5 % IACS |
What is C79600-O61?
C79600-O61 is C79600 heat treated to O61 — pick when maximum ductility for staking, riveting or secondary forming of machined parts is needed. C79600-O61 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 64% of copper alloy grades. Elongation at break is 32% and the elastic modulus is 115 GPa (16.7 Msi). C79600-O61 has a density of 8.52 g/cm³ (0.308 lb/in³), lighter than 63% of copper alloy grades. It melts at 875°C (1,607 °F). H02 is the default condition FabDigit quotes; O61 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 32%, better than 77% of copper alloy grades
- Easy to machine — 62/100, better than 75% of copper alloy grades
Limitations
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 88% of copper alloy grades
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- Low electrical conductivity — 9 % IACS, worse than 78% of copper alloy grades
C79600-O61 properties
Typical room-temperature values for C79600-O61; 20 are specific to this condition. Other listed values are C79600 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C79600-O61 has a density of 8.52 g/cm³ (0.308 lb/in³), lighter than 63% of copper alloy grades. It melts at 875°C (1,607 °F).
Mechanical12
C79600-O61 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 64% of copper alloy grades. Elongation at break is 32% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
C79600-O61 is rated for continuous service to 200°C (392 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 88% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C79600-O61 conducts electricity at 9 % IACS, worse than 78% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (56/100), worse than 81% of copper alloy grades.
Sustainability4
Producing a kilogram of C79600-O61 takes about 62 MJ of energy and emits 4.2 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C79600-O61's machinability is good (62/100, better than 75% of copper alloy grades); weldability poor (20/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C79600-O61
Is C79600 easy to machine?
Excellent free-cutting behaviour — lead breaks chips; run at brass-type speeds with sharp positive-rake tools and light oil; rating ≈70 % of C36000.
Can C79600 be welded?
Fusion welding is not recommended (lead causes hot shortness); join by soft soldering, low-temperature silver brazing or mechanical means.
Can C79600 be formed, bent or molded?
Hot extrude/forge at ~700–800 °C; cold forming limited by the beta phase and lead — keep bends generous and anneal between heavy operations.
What surface finishes work on C79600?
Polishes to a bright silver-white lustre; readily nickel-, chrome- or silver-plated, and often lacquered to prevent tarnish. Avoid ammonia-based cleaners (SCC risk).
C79600 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 | 43 – 46 | 44.5 |
| Niincludes Co | 9 – 11 | 10 |
| Pbfree-machining addition | 0.8 – 1.8 | 1.3 |
| Fe | ≤ 0.25 | 0.1 |
| Mn | ≤ 0.5 | 0.2 |
| Znremainder, nominally ~44% | balance | — |
C79600-O61 — frequently asked
What is C79600-O61 used for?
C79600-O61 is typically used for screw-machine rod stock, valve components, decorative hardware and plumbing fittings. In short: free-cutting nickel silver rod; 70% of C36000 machinability; bright finish, low conductivity.
What is the yield strength of C79600-O61?
C79600-O61 has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 400 MPa (58 ksi) — weaker than 64% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C79600-O61 easy to machine?
Reasonably — machinability is rated good (62/100, better than 75% of copper alloy grades). Excellent free-cutting behaviour — lead breaks chips; run at brass-type speeds with sharp positive-rake tools and light oil; rating ≈70 % of C36000.
Can C79600-O61 be welded?
Not readily — weldability is rated poor (20/100). Fusion welding is not recommended (lead causes hot shortness); join by soft soldering, low-temperature silver brazing or mechanical means.
What surface finishes work on C79600-O61?
Polishes to a bright silver-white lustre; readily nickel-, chrome- or silver-plated, and often lacquered to prevent tarnish. Avoid ammonia-based cleaners (SCC risk).
Can C79600-O61 be formed, bent or molded?
Hot extrude/forge at ~700–800 °C; cold forming limited by the beta phase and lead — keep bends generous and anneal between heavy operations.
What is the maximum service temperature of C79600-O61?
C79600-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 C79600-H02 and C79600-O61?
H02 is the default condition — the default stocked rod condition — best balance of strength, straightness and free-cutting behaviour for screw-machine parts. O61: pick when maximum ductility for staking, riveting or secondary forming of machined parts is needed. Yield strength is 400 MPa in H02 versus 165 MPa in O61.
Sources
- ASTM B151/B151M — Copper-Nickel-Zinc (Nickel Silver) Rod and Bar — ASTM International (2019)
- CDA Alloy Database — C79600 leaded nickel silver — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.