Copper Alloy C18900-H04 vs C18900-M20
Copper Alloy · C18900 temper comparison
C18900-H04 and C18900-M20 are two conditions of the same copper alloy grade, C18900: H04 (full hard) versus M20 (as hot rolled). The chemistry is identical, so every difference below comes from the condition. C18900-H04 is the stronger of the two: yield strength 370 MPa (53.7 ksi) against 130 MPa (18.9 ksi) for C18900-M20, about 185% more; tensile strength follows at 405 MPa (58.7 ksi) vs 285 MPa (41.3 ksi). In exchange, C18900-M20 is the more ductile: elongation 38% versus 8% for C18900-H04, and C18900-H04 is harder (115 HB vs 62 HB). C18900-M20 runs hotter in service (300°C vs 200°C continuous).
C18900-H04Choose it when strength drives the design.
C18900-M20Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C18900-H04 vs C18900-M20: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all copper alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all copper alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 117 GPa17 Msi · Shear Modulus 44 GPa6.4 Msi · Bulk Modulus 138 GPa20 Msi · Poisson's Ratio 0.34
Physical
Density and transition temperatures.
Same in both: Density 8.89 g/cm³0.32 lb/in³ · Melting Point (Solidus) 1,030°C1,886 °F · Liquidus Temperature 1,065°C1,949 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 385 J/kg·K0.09 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 17.6 µm/m·K9.8 µin/in·°F · Latent Heat of Fusion 205 J/g88.1 BTU/lb · Min Service Temperature -200°C-328 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.2 V · Corrosion Resistance 68 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 45 / 100 · Brazeability / Solderability 88 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 57 MJ/kg24,506 BTU/lb · Embodied Carbon (primary production) 3.7 kg CO₂/kg · Embodied Water 250 L/kg30 gal/lb · Typical Recycled Content 35%
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.
C18900-H04 vs C18900-M20 — frequently asked
Is C18900-H04 stronger than C18900-M20?
Yes. C18900-H04 has a typical yield strength of 370 MPa (53.7 ksi) against 130 MPa (18.9 ksi) for C18900-M20 — about 185% more. Tensile strength is 405 MPa (58.7 ksi) vs 285 MPa (41.3 ksi).
Which condition does FabDigit quote by default, H04 or M20?
H04 is the default C18900 condition in the FabDigit quote flow. 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, C18900-H04 or C18900-M20?
C18900-H04, by a small margin. Both rate poor for machinability — 32/100 against 25/100 for C18900-M20; for welding the order is C18900-M20 first (excellent, 85/100) then C18900-H04 (very good, 80/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C18900-H04 and C18900-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.