Steel SUP9 Annealed vs SUP9 Hardened & Tempered
Steel · SUP9 temper comparison
SUP9 Annealed and SUP9 Hardened & Tempered are two conditions of the same steel grade, SUP9: Annealed versus Hardened & Tempered (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. SUP9 Hardened & Tempered is the stronger of the two: yield strength 1,500 MPa (218 ksi) against 440 MPa (63.8 ksi) for SUP9 Annealed, about 3.4 times as much; tensile strength follows at 1,700 MPa (247 ksi) vs 760 MPa (110 ksi). In exchange, SUP9 Annealed is the more ductile: elongation 22% versus 6% for SUP9 Hardened & Tempered, and SUP9 Hardened & Tempered is harder (480 HB vs 217 HB). SUP9 Annealed runs hotter in service (250°C vs 180°C continuous). On the shop floor, SUP9 Annealed machines more easily (good vs poor) and SUP9 Annealed welds better (poor vs not recommended).
SUP9 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
SUP9 Hardened & TemperedChoose it when strength drives the design.
SUP9 Annealed vs SUP9 Hardened & Tempered: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel 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 steel 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.
SUP9 AnnealedSUP9 Hardened & Tempered
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, Vickers
Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 95 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 46 W/m·K26.6 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 11 / 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 50 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 55 L/kg6.6 gal/lb · Typical Recycled Content 30%
Strength versus weight
Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
SUP9 Annealed vs SUP9 Hardened & Tempered — frequently asked
Is SUP9 Hardened & Tempered stronger than SUP9 Annealed?
Yes. SUP9 Hardened & Tempered has a typical yield strength of 1,500 MPa (218 ksi) against 440 MPa (63.8 ksi) for SUP9 Annealed — about 3.4 times as much. Tensile strength is 1,700 MPa (247 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, Annealed or Hardened & Tempered?
Annealed is the default SUP9 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, SUP9 Annealed or SUP9 Hardened & Tempered?
SUP9 Annealed. Its machinability rates good (55/100) against poor (15/100) for SUP9 Hardened & Tempered; for welding the order is SUP9 Annealed first (poor, 30/100) then SUP9 Hardened & Tempered (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in SUP9 Annealed and SUP9 Hardened & Tempered 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.