Aluminum 3303-H18 vs 3303-O
Aluminum · 3303 temper comparison
3303-H18 and 3303-O are two conditions of the same aluminum grade, 3303: H18 (strain hardened, full hard) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. 3303-H18 is the stronger of the two: yield strength 185 MPa (26.8 ksi) against 42 MPa (6.09 ksi) for 3303-O, about 4.4 times as much; tensile strength follows at 200 MPa (29 ksi) vs 110 MPa (16 ksi). In exchange, 3303-O is the more ductile: elongation 33% versus 4% for 3303-H18, and 3303-H18 is harder (55 HB vs 28 HB). 3303-O conducts heat better (193 W/m·K vs 155 W/m·K). On the shop floor, 3303-H18 machines more easily (fair vs poor) and 3303-O welds better (excellent vs very good).
3303-H18Choose it when strength drives the design, or when the part is machined in volume.
3303-OChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
3303-H18 vs 3303-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 69 GPa10 Msi · Shear Modulus 25 GPa3.6 Msi · Bulk Modulus 69 GPa10 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.73 g/cm³0.1 lb/in³ · Melting Point (Solidus) 643°C1,189 °F · Liquidus Temperature 654°C1,209 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 893 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 23.2 µm/m·K12.9 µin/in·°F · Latent Heat of Fusion 390 J/g168 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -196°C-321 °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) -0.83 V · Corrosion Resistance 70 / 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: Brazeability / Solderability 90 / 100 · Polishability 50 / 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 40%
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.
3303-H18 vs 3303-O — frequently asked
Is 3303-H18 stronger than 3303-O?
Yes. 3303-H18 has a typical yield strength of 185 MPa (26.8 ksi) against 42 MPa (6.09 ksi) for 3303-O — about 4.4 times as much. Tensile strength is 200 MPa (29 ksi) vs 110 MPa (16 ksi).
Which condition does FabDigit quote by default, H18 or O?
O is the default 3303 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, 3303-H18 or 3303-O?
3303-H18. Its machinability rates fair (45/100) against poor (30/100) for 3303-O; for welding the order is 3303-O first (excellent, 90/100) then 3303-H18 (very good, 80/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 3303-H18 and 3303-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.