Copper Alloy C28000-M20
Finish state
UNS C28000 · ASTM B36, B171 · EN CW509L, CuZn40 · JIS C2800 · GB H62
M20 = as hot rolled
Economical mill condition for thick Muntz plate, tube sheets and marine sheathing.
Values for the M20 condition
Other C28000 tempers and conditions
C28000 is listed in 9 conditions; see the grade overview at C28000.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Most-stocked soft condition for sheet/plate that must be bent, spun or deep-formed before service. | 145 | 372 | 45 | 75 HB | 28 % IACS |
As hot extruded | Standard supply condition for hot-extruded Muntz rod, hex and architectural sections. | 145 | 372 | 45 | 75 HB | 28 % IACS |
M20This page As hot rolled | Economical mill condition for thick Muntz plate, tube sheets and marine sheathing. | 152 | 372 | 45 | 80 HB | 28 % IACS |
1/8 Hard | Lightly cold-worked (~10% reduction) Muntz metal sheet/plate — small strength gain over hot-rolled temper while retaining good bending and forming ability. | 205 | 395 | 38 | 95 HB | 28 % IACS |
Quarter hard | Choose when moderate stiffness/strength is needed but some bending is still required. | 275 | 400 | 25 | 105 HB | 27 % IACS |
Half hard | Standard strength condition for flat sheet, architectural panels and lightly formed parts. | 359 | 428 | 10 | 130 HB | 28 % IACS |
Three-quarter hard | Heavily cold-rolled (~30–35% reduction) Muntz metal with high strength and spring-like stiffness, limited to gentle forming operations. | 380 | 505 | 12 | 135 HB | 28 % IACS |
Full hard | For flat springs, wear plates and stiff strip where no further forming is needed. | 415 | 500 | 6 | 150 HB | 27 % IACS |
Extra hard | 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. | 450 | 570 | 6 | 155 HB | 28 % IACS |
What is C28000-M20?
C28000-M20 is C28000 supplied in the M20 condition — economical mill condition for thick Muntz plate, tube sheets and marine sheathing. C28000-M20 has a yield strength of 152 MPa (22 ksi) and a tensile strength of 372 MPa (54 ksi) — weaker than 67% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 105 GPa (15.2 Msi). C28000-M20 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). O is the default condition FabDigit quotes; M20 is available on request or by drawing note.
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-M20 properties
Typical room-temperature values for C28000-M20; 20 are specific to this condition. Other listed values are C28000 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C28000-M20 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-M20 has a yield strength of 152 MPa (22 ksi) and a tensile strength of 372 MPa (54 ksi) — weaker than 67% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C28000-M20 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
C28000-M20 conducts electricity at 28 % IACS, better than 69% 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-M20 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-M20's machinability is good (55/100, better than 71% of copper alloy grades); weldability fair (50/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C28000-M20
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-M20 — frequently asked
What is C28000-M20 used for?
C28000-M20 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-M20?
C28000-M20 has a typical yield strength of 152 MPa (22 ksi) and a tensile strength of 372 MPa (54 ksi) — weaker than 67% of copper alloy grades. Strength varies by condition: see the 9 listed tempers.
Is C28000-M20 easy to machine?
Reasonably — machinability is rated good (55/100, better than 71% 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-M20 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-M20?
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-M20 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-M20?
C28000-M20 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-M20?
Yes — C28000-M20 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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.