Steel A6 As-Quenched vs A6 Hardened & Tempered
Steel · A6 temper comparison
A6 As-Quenched and A6 Hardened & Tempered are two conditions of the same steel grade, A6: As-Quenched (air hardened from 845–870 °C, untempered) versus Hardened & Tempered (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. A6 As-Quenched is the stronger of the two: yield strength 2,000 MPa (290 ksi) against 1,800 MPa (261 ksi) for A6 Hardened & Tempered, about 11% more; tensile strength follows at 2,300 MPa (334 ksi) vs 2,100 MPa (305 ksi). In exchange, A6 Hardened & Tempered is the more ductile: elongation 2% versus 0.5% for A6 As-Quenched, and A6 As-Quenched is harder (690 HB vs 235 HB). A6 Hardened & Tempered runs hotter in service (175°C vs 150°C continuous) and A6 Hardened & Tempered conducts heat better (27 W/m·K vs 24 W/m·K). On the shop floor, A6 Hardened & Tempered welds better (poor vs not recommended).
A6 As-QuenchedChoose it when strength drives the design.
A6 Hardened & TemperedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
A6 As-Quenched vs A6 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.
A6 As-QuenchedA6 Hardened & Tempered
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
Same in both: Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 99 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.83 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,480°C2,696 °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 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
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
Weldability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 5% · Castability 20 / 100 · Brazeability / Solderability 35 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 45%
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.
A6 As-Quenched vs A6 Hardened & Tempered — frequently asked
Is A6 As-Quenched stronger than A6 Hardened & Tempered?
Yes. A6 As-Quenched has a typical yield strength of 2,000 MPa (290 ksi) against 1,800 MPa (261 ksi) for A6 Hardened & Tempered — about 11% more. Tensile strength is 2,300 MPa (334 ksi) vs 2,100 MPa (305 ksi).
Which condition does FabDigit quote by default, As-Quenched or Hardened & Tempered?
Annealed is the default A6 condition in the FabDigit quote flow (neither As-Quenched nor Hardened & Tempered). 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, A6 As-Quenched or A6 Hardened & Tempered?
A6 Hardened & Tempered, by a small margin. Both rate not recommended for machinability — 8/100 against 3/100 for A6 As-Quenched; for welding the order is A6 Hardened & Tempered first (poor, 20/100) then A6 As-Quenched (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A6 As-Quenched and A6 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.