Copper Alloy C28000 · temper · default condition
Copper Alloy C28000-O
Properties of the O condition, compared with the other C28000 tempers.
Most-stocked soft condition for sheet/plate that must be bent, spun or deep-formed before service.
What is C28000-O?
C28000-O is C28000 in the O temper — most-stocked soft condition for sheet/plate that must be bent, spun or deep-formed before service. C28000-O has a yield strength of 145 MPa (21 ksi) and a tensile strength of 372 MPa (54 ksi) — weaker than 71% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 105 GPa (15.2 Msi). C28000-O has a density of 8.39 g/cm³ (0.303 lb/in³), lighter than 76% of copper alloy grades. It melts at 900°C (1,652 °F).
Advantages
- Low embodied carbon — 3 kg CO₂/kg, better than 97% of copper alloy grades
- Ductile — tolerates forming and impact — 45%, better than 91% of copper alloy grades
Limitations
- Needs corrosion protection — 45/100, worse than 98% of copper alloy grades
C28000-O properties
Typical room-temperature values for C28000-O — 12 properties are specific to this condition; the rest are grade-level values shared by every C28000 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C28000-O has a density of 8.39 g/cm³ (0.303 lb/in³), lighter than 76% of copper alloy grades. It melts at 900°C (1,652 °F).
Mechanical11
C28000-O has a yield strength of 145 MPa (21 ksi) and a tensile strength of 372 MPa (54 ksi) — weaker than 71% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C28000-O 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 69% of copper alloy grades. Thermal expansion is 20.8 µm/m·K (11.6 µin/in·°F).
Electrical3
C28000-O conducts electricity at 28 % IACS, better than 68% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 98% of copper alloy grades.
Sustainability4
Producing a kilogram of C28000-O takes about 48 MJ of energy and emits 3 kg of CO₂ — less than 92% of copper alloy grades. Typical recycled content is 70%.
Manufacturability8
C28000-O's machinability is good (55/100, better than 72% of copper alloy grades); weldability fair (50/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C28000 tempers and conditions
C28000 is also supplied in 8 other conditions. The full side-by-side table is on the C28000 overview.
- ODefaultMost-stocked soft condition for sheet/plate that must be bent, spun or deep-formed before service.145 MPa yield · 75 HB
- H06Maximum practical cold-work temper for 60/40 brass — highest strength and hardness with very low ductility, used for flat springs, stiff strip and wear plates.450 MPa yield · 155 HB
- H03Heavily cold-rolled (~30–35% reduction) Muntz metal with high strength and spring-like stiffness, limited to gentle forming operations.380 MPa yield · 135 HB
- H02Standard strength condition for flat sheet, architectural panels and lightly formed parts.359 MPa yield · 130 HB
- H01Choose when moderate stiffness/strength is needed but some bending is still required.275 MPa yield · 105 HB
- H00Lightly cold-worked (~10% reduction) Muntz metal sheet/plate — small strength gain over hot-rolled temper while retaining good bending and forming ability.205 MPa yield · 95 HB
Working with C28000-O
Is C28000 easy to machine?
Machines to a rating of about 40 % of free-cutting C36000 — expect gummier chips than leaded brass; use sharp positive-rake tools, high speed and light feeds with emulsion coolant.
Can C28000 be welded?
Resistance and braze/solder joining are good; fusion (GTAW/GMAW) is only fair because of zinc fuming and porosity — use low heat input, ventilation and a Cu-Si or Cu-Sn filler.
Can C28000 be formed, bent or molded?
Excellent hot workability at 650–780 °C (hot rolling, extrusion, forging); cold bending is limited in H02/H04 — anneal at 425–600 °C between severe draws.
What surface finishes work on C28000?
Polishes and buffs to a bright yellow finish; stress-relieve (about 250–300 °C) before service and protect with benzotriazole/lacquer or nickel-chrome plating to prevent dezincification and SCC.
C28000 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 |
|---|---|---|
| CuASTM B36 / UNS C28000 | 59 – 63 | 60 |
| Pb | ≤ 0.3 | 0.05 |
| Fe | ≤ 0.07 | 0.03 |
| Znremainder ≈ 37–41 % | balance | — |
C28000-O — frequently asked
What is C28000-O used for?
C28000-O is typically used for architectural cladding and trim panels, heat exchanger and condenser tube sheets, hot-extruded rod and forged fittings, marine hardware and hull sheathing, valve stems and pump components and brazing and filler rod stock. In short: muntz brass forming sheet.
What is the yield strength of C28000-O?
C28000-O has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 372 MPa (54 ksi) — weaker than 71% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C28000-O easy to machine?
Reasonably — machinability is rated good (55/100, better than 72% of copper alloy grades). Machines to a rating of about 40 % of free-cutting C36000 — expect gummier chips than leaded brass; use sharp positive-rake tools, high speed and light feeds with emulsion coolant.
Can C28000-O be welded?
With care — weldability is rated fair (50/100). Resistance and braze/solder joining are good; fusion (GTAW/GMAW) is only fair because of zinc fuming and porosity — use low heat input, ventilation and a Cu-Si or Cu-Sn filler.
What surface finishes work on C28000-O?
Polishes and buffs to a bright yellow finish; stress-relieve (about 250–300 °C) before service and protect with benzotriazole/lacquer or nickel-chrome plating to prevent dezincification and SCC.
Can C28000-O be formed, bent or molded?
Excellent hot workability at 650–780 °C (hot rolling, extrusion, forging); cold bending is limited in H02/H04 — anneal at 425–600 °C between severe draws.
What is the maximum service temperature of C28000-O?
C28000-O 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 C28000-O and C28000-H06?
O is the default condition — most-stocked soft condition for sheet/plate that must be bent, spun or deep-formed before service. H06: maximum practical cold-work temper for 60/40 brass — highest strength and hardness with very low ductility, used for flat springs, stiff strip and wear plates. Yield strength is 145 MPa in O versus 450 MPa in H06.
Can FabDigit make parts in C28000-O?
Yes — C28000-O is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar — ASTM (2018)
- ASTM B171/B171M — Copper-Alloy Plate for Condensers and Heat Exchangers — ASTM (2018)
- CDA Alloy Datasheet C28000 (Muntz Metal) — Copper Development Association (copper.org) (2024)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- GB/T 2040 / GB/T 4423 — (H62) — 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.