Aluminum 4104-H18 vs 4104-O
Aluminum · 4104 temper comparison
4104-H18 and 4104-O are two conditions of the same aluminum grade, 4104: H18 (strain hardened, full hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. 4104-H18 is the stronger of the two: yield strength 220 MPa (31.9 ksi) against 70 MPa (10.2 ksi) for 4104-O, about 3.1 times as much; tensile strength follows at 240 MPa (34.8 ksi) vs 165 MPa (23.9 ksi). In exchange, 4104-O is the more ductile: elongation 18% versus 2% for 4104-H18, and 4104-H18 is harder (72 HB vs 45 HB). 4104-O runs hotter in service (150°C vs 100°C continuous). On the shop floor, 4104-H18 machines more easily (fair vs poor).
4104-H18Choose it when strength drives the design, or when the part is machined in volume.
4104-OChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
4104-H18 vs 4104-O: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum 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 aluminum 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
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 72 GPa10.4 Msi · Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 71 GPa10.3 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.66 g/cm³0.1 lb/in³ · Melting Point (Solidus) 559°C1,038 °F · Liquidus Temperature 596°C1,105 °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 880 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 20 µm/m·K11.1 µin/in·°F · Latent Heat of Fusion 450 J/g193 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.82 V
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 80 / 100 · Brazeability / Solderability 97 / 100 · Polishability 30 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,150 L/kg138 gal/lb · Typical Recycled Content 20%
Strength versus weight
Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
4104-H18 vs 4104-O — frequently asked
Is 4104-H18 stronger than 4104-O?
Yes. 4104-H18 has a typical yield strength of 220 MPa (31.9 ksi) against 70 MPa (10.2 ksi) for 4104-O — about 3.1 times as much. Tensile strength is 240 MPa (34.8 ksi) vs 165 MPa (23.9 ksi).
Which condition does FabDigit quote by default, H18 or O?
O is the default 4104 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, 4104-H18 or 4104-O?
4104-H18. Its machinability rates fair (38/100) against poor (28/100) for 4104-O; for welding the order is 4104-O first (fair, 35/100) then 4104-H18 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4104-H18 and 4104-O 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.