Copper Alloy C36800-O61
Heat-treated state
UNS C36800 · ASTM B121
O61 = annealed
Softest condition, used when maximum ductility for bending or expanding is needed.
Values for the O61 condition
Other C36800 tempers and conditions
C36800 is listed in 4 conditions; see the grade overview at C36800.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O61This page Annealed | Softest condition, used when maximum ductility for bending or expanding is needed. | 115 | 340 | 52 | 80 HB | 28 % IACS |
M20Default As hot rolled | Standard condition for condenser tube sheets and heavy plate per ASTM B171. | 140 | 370 | 45 | 100 HB | 28 % IACS |
As hot extruded | Choose for screw-machine rod and extruded shapes where free-cutting behaviour matters. | 160 | 380 | 40 | 105 HB | 28 % IACS |
Quarter hard | Light cold work for straighter, stiffer bar or plate where some strength gain is wanted; cold ductility of the α+β structure is limited. | 250 | 420 | 25 | 125 HB | 27 % IACS |
What is C36800-O61?
C36800-O61 is C36800 heat treated to O61 — softest condition, used when maximum ductility for bending or expanding is needed. C36800-O61 has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 52% and the elastic modulus is 105 GPa (15.2 Msi). C36800-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 — 52%, better than 97% of copper alloy grades
- Easy to machine — 62/100, better than 75% of copper alloy grades
Limitations
- Low strength — 115 MPa (16.7 ksi), worse than 80% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
C36800-O61 properties
Typical room-temperature values for C36800-O61; 20 are specific to this condition. Other listed values are C36800 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C36800-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
C36800-O61 has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 80% of copper alloy grades. Elongation at break is 52% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C36800-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
C36800-O61 conducts electricity at 28 % IACS, better than 69% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C36800-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 65%.
Manufacturability7
C36800-O61's machinability is good (62/100, better than 75% of copper alloy grades); weldability poor (25/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C36800-O61
Is C36800 easy to machine?
Free-cutting at ~60% of AISI 1212 — use positive-rake carbide or HSS brass geometry, high speed, light feed, sulfur-free coolant; chips break well thanks to the lead.
Can C36800 be welded?
Fusion welding is not recommended (lead causes hot cracking and porosity); join by soldering, silver brazing or mechanical means, and avoid ammonia-bearing fluxes.
Can C36800 be formed, bent or molded?
Excellent hot workability at 650–800 °C (extrusion, forging, hot rolling); cold bending/forming is limited by the β phase and lead — anneal at 425–600 °C before severe cold work.
What surface finishes work on C36800?
Takes bright dip, mechanical polishing, tin/nickel/chrome plating and lacquering well; do not anodize — de-lead (fluoboric etch) before plating to avoid blistering.
C36800 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 |
| Pbfree-machining addition | 0.25 – 0.7 | 0.45 |
| Fe | ≤ 0.15 | — |
| Pdezincification inhibitor | 0.02 – 0.1 | 0.05 |
| Zn | balance | — |
C36800-O61 — frequently asked
What is C36800-O61 used for?
C36800-O61 is typically used for screw machine parts, valve stems and hardware fittings. In short: best-machining Muntz metal; screw-machine 60/40 brass; high-lead free-cutting grade.
What is the yield strength of C36800-O61?
C36800-O61 has a typical yield strength of 115 MPa (16.7 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 80% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is C36800-O61 easy to machine?
Reasonably — machinability is rated good (62/100, better than 75% of copper alloy grades). Free-cutting at ~60% of AISI 1212 — use positive-rake carbide or HSS brass geometry, high speed, light feed, sulfur-free coolant; chips break well thanks to the lead.
Can C36800-O61 be welded?
Not readily — weldability is rated poor (25/100). Fusion welding is not recommended (lead causes hot cracking and porosity); join by soldering, silver brazing or mechanical means, and avoid ammonia-bearing fluxes.
What surface finishes work on C36800-O61?
Takes bright dip, mechanical polishing, tin/nickel/chrome plating and lacquering well; do not anodize — de-lead (fluoboric etch) before plating to avoid blistering.
Can C36800-O61 be formed, bent or molded?
Excellent hot workability at 650–800 °C (extrusion, forging, hot rolling); cold bending/forming is limited by the β phase and lead — anneal at 425–600 °C before severe cold work.
What is the maximum service temperature of C36800-O61?
C36800-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 C36800-M20 and C36800-H01?
M20 is the default condition — standard condition for condenser tube sheets and heavy plate per ASTM B171. H01: light cold work for straighter, stiffer bar or plate where some strength gain is wanted; cold ductility of the α+β structure is limited. Yield strength is 140 MPa in M20 versus 250 MPa in H01.
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)
- ASM Handbook Vol.13B — Corrosion: Materials (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.