Steel D3 Annealed vs D3 Hardened & Tempered
Steel · D3 temper comparison
D3 Annealed and D3 Hardened & Tempered are two conditions of the same steel grade, D3: Annealed versus Hardened & Tempered (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. D3 Hardened & Tempered is the stronger of the two: tensile strength 2,100 MPa (305 ksi) against 800 MPa (116 ksi) for D3 Annealed, about 163% more. In exchange, D3 Annealed is the more ductile: elongation 14% versus 0.5% for D3 Hardened & Tempered, and D3 Hardened & Tempered is harder (62 HRC vs 20 HRC). D3 Annealed runs hotter in service (200°C vs 180°C continuous). On the shop floor, D3 Annealed machines more easily (poor vs not recommended).
D3 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
D3 Hardened & TemperedChoose it when strength drives the design.
D3 Annealed vs D3 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.
D3 AnnealedD3 Hardened & Tempered
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Yield Strength (0.2% offset) 460 MPa66.7 ksi · Reduction in Area 30% · Hardness, Brinell 225 HB · Hardness, Rockwell B 98 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,230°C2,246 °F · Liquidus Temperature 1,400°C2,552 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 20 W/m·K11.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 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 2.6 % IACS · Electrical Resistivity 6.5×10⁻⁷ Ω·m25.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 15 / 100 · Formability (cold) 12 / 100 · Brazeability / Solderability 25 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.8 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 40%
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.
D3 Annealed vs D3 Hardened & Tempered — frequently asked
Is D3 Hardened & Tempered stronger than D3 Annealed?
Yes. D3 Hardened & Tempered has a typical tensile strength of 2,100 MPa (305 ksi) against 800 MPa (116 ksi) for D3 Annealed — about 163% more.
Which condition does FabDigit quote by default, Annealed or Hardened & Tempered?
Annealed is the default D3 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, D3 Annealed or D3 Hardened & Tempered?
D3 Annealed. Its machinability rates poor (25/100) against not recommended (5/100) for D3 Hardened & Tempered.
Ready to make it?
Upload a CAD file and FabDigit prices the part in D3 Annealed and D3 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.