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Steel A6 Annealed vs A6 Hardened & Tempered

Steel · A6 temper comparison

A6 Annealed and A6 Hardened & Tempered are two conditions of the same steel grade, A6: Annealed versus Hardened & Tempered (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. A6 Hardened & Tempered is the stronger of the two: yield strength 1,800 MPa (261 ksi) against 415 MPa (60.2 ksi) for A6 Annealed, about 4.3 times as much; tensile strength follows at 2,100 MPa (305 ksi) vs 725 MPa (105 ksi). In exchange, A6 Annealed is the more ductile: elongation 22% versus 2% for A6 Hardened & Tempered, and A6 Hardened & Tempered is harder (675 HV vs 245 HV). A6 Annealed runs hotter in service (200°C vs 175°C continuous). On the shop floor, A6 Annealed machines more easily (fair vs not recommended).

A6 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

A6 Hardened & TemperedChoose it when strength drives the design.

A6 Annealed vs A6 Hardened & Tempered: properties

A6 AnnealedA6 Hardened & Tempered

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

725 MPa105 ksi
2,100 MPa305 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
1,800 MPa261 ksi

Elongation at Break

22%
2%

Compressive Strength

450 MPa65.3 ksi
2,900 MPa421 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
750 MPa109 ksi

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
10 J7.4 ft·lbf

Hardness, Vickers

245 HV
675 HV

Same in both: Elastic (Young's) Modulus 203 GPa29.4 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 45% · Shear Strength 470 MPa68.2 ksi · Hardness, Brinell 235 HB · 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.

Max Service Temperature (continuous)

200°C392 °F
175°C347 °F

Same in both: Thermal Conductivity 27 W/m·K15.6 BTU/hr·ft·°F · 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.

Same in both: Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 15 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

50 / 100
8 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
5%

Same in both: Weldability 20 / 100 · Formability (cold) 30 / 100 · 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleA6

A6 Annealed vs A6 Hardened & Tempered — frequently asked

Is A6 Hardened & Tempered stronger than A6 Annealed?

Yes. A6 Hardened & Tempered has a typical yield strength of 1,800 MPa (261 ksi) against 415 MPa (60.2 ksi) for A6 Annealed — about 4.3 times as much. Tensile strength is 2,100 MPa (305 ksi) vs 725 MPa (105 ksi).

Which condition does FabDigit quote by default, Annealed or Hardened & Tempered?

Annealed is the default A6 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, A6 Annealed or A6 Hardened & Tempered?

A6 Annealed. Its machinability rates fair (50/100) against not recommended (8/100) for A6 Hardened & Tempered.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A6 Annealed 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.