Copper Alloy C36600-O61
Heat-treated state
UNS C36600 · ASTM B121
O61 = annealed
Use when maximum ductility is needed for bending or when residual stress must be removed before machining.
Values for the O61 condition
Other C36600 tempers and conditions
C36600 is listed in 5 conditions; see the grade overview at C36600.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O61This page Annealed | Use when maximum ductility is needed for bending or when residual stress must be removed before machining. | 125 | 345 | 50 | 70 HB | 28 % IACS |
M20Default As hot rolled | Standard supply condition for ASTM B171 condenser and heat-exchanger tube plate; best combination of strength and drillability. | 138 | 372 | 45 | 80 HB | 28 % IACS |
As hot extruded | Pick for extruded bar, rod or sections that will be machined rather than formed. | 145 | 365 | 40 | 80 HB | 28 % IACS |
Quarter hard | Light cold reduction for higher yield strength in thin plate and strip where only mild forming follows. | 275 | 420 | 25 | 110 HB | 27 % IACS |
Half hard | Highest practical strength condition for this alloy; for flat parts machined or only slightly bent. | 350 | 470 | 15 | 130 HB | 27 % IACS |
What is C36600-O61?
C36600-O61 is C36600 heat treated to O61 — use when maximum ductility is needed for bending or when residual stress must be removed before machining. C36600-O61 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 345 MPa (50 ksi) — weaker than 77% of copper alloy grades. Elongation at break is 50% and the elastic modulus is 105 GPa (15.2 Msi). C36600-O61 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 885°C (1,625 °F). M20 is the default condition FabDigit quotes; O61 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 50%, better than 97% of copper alloy grades
Limitations
- Low strength — 125 MPa (18.1 ksi), worse than 77% of copper alloy grades
C36600-O61 properties
Typical room-temperature values for C36600-O61; 20 are specific to this condition. Other listed values are C36600 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C36600-O61 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 885°C (1,625 °F).
Mechanical11
C36600-O61 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 345 MPa (50 ksi) — weaker than 77% of copper alloy grades. Elongation at break is 50% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C36600-O61 is rated for continuous service to 200°C (392 °F). It conducts heat at 123 W/m·K (71.1 BTU/hr·ft·°F), better than 70% of copper alloy grades. Thermal expansion is 20.8 µm/m·K (11.6 µin/in·°F).
Electrical3
C36600-O61 conducts electricity at 28 % IACS, better than 69% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (57/100), worse than 80% of copper alloy grades.
Sustainability4
Producing a kilogram of C36600-O61 takes about 62 MJ of energy and emits 3.8 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 55%.
Manufacturability7
C36600-O61's machinability is good (55/100, better than 71% of copper alloy grades); weldability fair (40/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C36600-O61
Is C36600 easy to machine?
Free-machining enough for gang-drilling tube-plate hole patterns; use sharp carbide or HSS tools, 0–5° rake, generous coolant — chips are short but stringier than C36000.
Can C36600 be welded?
Fusion welding is not recommended (lead causes hot cracking and zinc fumes); join by soldering or silver brazing, with fume extraction.
Can C36600 be formed, bent or molded?
Excellent hot working at 650–760 °C; cold forming limited by the β phase — anneal at 425–600 °C and avoid tight bend radii.
What surface finishes work on C36600?
Takes a good mechanical polish and accepts nickel/tin/chrome plating; a light acid pickle removes hot-rolling oxide, and stress-relief annealing reduces ammonia SCC risk.
C36600 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 | 58 – 61 | 59.5 |
| Pbmachinability addition | 0.25 – 0.7 | 0.45 |
| Fe | ≤ 0.15 | — |
| Asdezincification inhibitor | 0.02 – 0.1 | 0.05 |
| Zn | balance | — |
C36600-O61 — frequently asked
What is C36600-O61 used for?
C36600-O61 is typically used for architectural trim, valve stems and condenser hardware. In short: low-lead Muntz metal; 60/40 strength, moderate machining; strong hot workability.
What is the yield strength of C36600-O61?
C36600-O61 has a typical yield strength of 125 MPa (18.1 ksi) and a tensile strength of 345 MPa (50 ksi) — weaker than 77% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C36600-O61 easy to machine?
Reasonably — machinability is rated good (55/100, better than 71% of copper alloy grades). Free-machining enough for gang-drilling tube-plate hole patterns; use sharp carbide or HSS tools, 0–5° rake, generous coolant — chips are short but stringier than C36000.
Can C36600-O61 be welded?
With care — weldability is rated fair (40/100). Fusion welding is not recommended (lead causes hot cracking and zinc fumes); join by soldering or silver brazing, with fume extraction.
What surface finishes work on C36600-O61?
Takes a good mechanical polish and accepts nickel/tin/chrome plating; a light acid pickle removes hot-rolling oxide, and stress-relief annealing reduces ammonia SCC risk.
Can C36600-O61 be formed, bent or molded?
Excellent hot working at 650–760 °C; cold forming limited by the β phase — anneal at 425–600 °C and avoid tight bend radii.
What is the maximum service temperature of C36600-O61?
C36600-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 C36600-M20 and C36600-H02?
M20 is the default condition — standard supply condition for ASTM B171 condenser and heat-exchanger tube plate; best combination of strength and drillability. H02: highest practical strength condition for this alloy; for flat parts machined or only slightly bent. Yield strength is 138 MPa in M20 versus 350 MPa in H02.
Sources
- ASTM B171/B171M — Copper-Alloy Plate and Sheet for Pressure Vessels, Condensers, and Heat Exchangers — ASTM International (2018)
- ASTM B121/B121M — Leaded Brass Plate, Sheet, Strip and Rolled Bar — ASTM International (2020)
- CDA Alloy Datasheet C36500–C36800 (Leaded Muntz Metal) — 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.