Aluminum 5A12-H18 vs 5A12-O
Aluminum · 5A12 temper comparison
5A12-H18 and 5A12-O are two conditions of the same aluminum grade, 5A12: H18 (strain hardened, full hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. 5A12-H18 is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 210 MPa (30.5 ksi) for 5A12-O, about 110% more; tensile strength follows at 520 MPa (75.4 ksi) vs 400 MPa (58 ksi). In exchange, 5A12-O is the more ductile: elongation 18% versus 4% for 5A12-H18, and 5A12-H18 is harder (140 HB vs 95 HB). On the shop floor, 5A12-H18 machines more easily (good vs fair) and 5A12-O welds better (very good vs good).
5A12-H18Choose it when strength drives the design, or when the part is machined in volume.
5A12-OChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
5A12-H18 vs 5A12-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
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 69 GPa10 Msi · Shear Modulus 26 GPa3.8 Msi · Bulk Modulus 67 GPa9.7 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.6 g/cm³0.09 lb/in³ · Melting Point (Solidus) 565°C1,049 °F · Liquidus Temperature 620°C1,148 °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 900 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 25 µm/m·K13.9 µin/in·°F · Latent Heat of Fusion 390 J/g168 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) -0.87 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 25 / 100 · Brazeability / Solderability 10 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,200 L/kg144 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.
5A12-H18 vs 5A12-O — frequently asked
Is 5A12-H18 stronger than 5A12-O?
Yes. 5A12-H18 has a typical yield strength of 440 MPa (63.8 ksi) against 210 MPa (30.5 ksi) for 5A12-O — about 110% more. Tensile strength is 520 MPa (75.4 ksi) vs 400 MPa (58 ksi).
Which condition does FabDigit quote by default, H18 or O?
O is the default 5A12 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, 5A12-H18 or 5A12-O?
5A12-H18. Its machinability rates good (58/100) against fair (42/100) for 5A12-O; for welding the order is 5A12-O first (very good, 72/100) then 5A12-H18 (good, 62/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 5A12-H18 and 5A12-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.