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Copper Alloy C28500-H04 vs C28500-M20

Copper Alloy · C28500 temper comparison

C28500-H04 and C28500-M20 are two conditions of the same copper alloy grade, C28500: H04 (full hard) versus M20 (as hot rolled). The chemistry is identical, so every difference below comes from the condition. C28500-H04 is the stronger of the two: yield strength 410 MPa (59.5 ksi) against 150 MPa (21.8 ksi) for C28500-M20, about 173% more; tensile strength follows at 540 MPa (78.3 ksi) vs 380 MPa (55.1 ksi). In exchange, C28500-M20 is the more ductile: elongation 45% versus 10% for C28500-H04, and C28500-H04 is harder (150 HB vs 72 HB). C28500-M20 runs hotter in service (200°C vs 120°C continuous). On the shop floor, C28500-H04 machines more easily (good vs fair).

C28500-H04Choose it when strength drives the design, or when the part is machined in volume.

C28500-M20Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C28500-H04 vs C28500-M20: properties

C28500-H04C28500-M20

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

540 MPa78.3 ksi
380 MPa55.1 ksi

Yield Strength (0.2% offset)

410 MPa59.5 ksi
150 MPa21.8 ksi

Elongation at Break

10%
45%

Reduction in Area

30%
52%

Shear Strength

330 MPa47.9 ksi
260 MPa37.7 ksi

Fatigue Strength (Endurance Limit)

165 MPa23.9 ksi
125 MPa18.1 ksi

Charpy V-Notch Impact (RT)

18 J13.3 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

150 HB
72 HB

Hardness, Rockwell B

82 HRB
37 HRB

Hardness, Vickers

158 HV
76 HV

Same in both: Elastic (Young's) Modulus 105 GPa15.2 Msi · Shear Modulus 39 GPa5.7 Msi · Bulk Modulus 111 GPa16.1 Msi · Poisson's Ratio 0.34

Physical

Density and transition temperatures.

Same in both: Density 8.39 g/cm³0.3 lb/in³ · Melting Point (Solidus) 899°C1,650 °F · Liquidus Temperature 904°C1,659 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

118 W/m·K68.2 BTU/hr·ft·°F
123 W/m·K71.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

120°C248 °F
200°C392 °F

Same in both: Specific Heat Capacity 375 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 20.8 µm/m·K11.6 µin/in·°F · Latent Heat of Fusion 170 J/g73.1 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

26 % IACS
28 % IACS

Electrical Resistivity

6.6×10⁻⁸ Ω·m2.6 µΩ·in
6.2×10⁻⁸ Ω·m2.44 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

40 / 100
45 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.27 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
40%

Weldability

38 / 100
45 / 100

Formability (cold)

12 / 100
35 / 100

Same in both: Castability 60 / 100 · Brazeability / Solderability 80 / 100 · Polishability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 3.3 kg CO₂/kg · Embodied Water 250 L/kg30 gal/lb · Typical Recycled Content 50%

Strength versus weight

Yield strength against density for every copper alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

501002005001,0007.588.599.5Density (g/cm³)Yield strength (MPa) — log scaleC28500

C28500-H04 vs C28500-M20 — frequently asked

Is C28500-H04 stronger than C28500-M20?

Yes. C28500-H04 has a typical yield strength of 410 MPa (59.5 ksi) against 150 MPa (21.8 ksi) for C28500-M20 — about 173% more. Tensile strength is 540 MPa (78.3 ksi) vs 380 MPa (55.1 ksi).

Which condition does FabDigit quote by default, H04 or M20?

M30 is the default C28500 condition in the FabDigit quote flow (neither H04 nor M20). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, C28500-H04 or C28500-M20?

C28500-H04. Its machinability rates good (55/100) against fair (45/100) for C28500-M20; for welding the order is C28500-M20 first (fair, 45/100) then C28500-H04 (fair, 38/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C28500-H04 and C28500-M20 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.